4l80e hydraulic book

4L80-E

HYDRA-MATIC

CONTENTSINTRODUCTION ..................................................................................... 3 HOW TO USE THIS BOOK ...................................................................... 4 UNDERSTANDING THE GRAPHICS ....................................................... 6 TRANSMISSION CUTAWAY VIEW (FOLDOUT) ....................................... 8 GENERAL DESCRIPTION ....................................................................... 9 PRICIPLES OF OPERATION .................................................................. 9A MAJOR MECHANICAL COMPONENTS (FOLDOUT) ...................... 10 RANGE REFERENCE CHART ......................................................... 11 TORQUE CONVERTER .................................................................. 12 APPLY COMPONENTS ................................................................. 15 PLANETARY GEAR SETS ............................................................. 26 HYDRAULIC CONTROL COMPONENTS ........................................ 28 ELECTRICAL COMPONENTS ........................................................ 39 POWER FLOW ...................................................................................... 47 COMPLETE HYDRAULIC CIRCUITS ..................................................... 75 LUBRICATION POINTS ....................................................................... 102 BUSHING & BEARING LOCATIONS ................................................... 103 SEAL LOCATIONS .............................................................................. 104 ILLUSTRATED PARTS LIST ................................................................ 105 BASIC SPECIFICATIONS .................................................................... 118 PRODUCT DESIGNATION SYSTEM ................................................... 119 GLOSSARY ........................................................................................ 120 ABBREVIATIONS ............................................................................... 122 INDEX ................................................................................................ 123

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PREFACEThe Hydra-matic 4L80-E Technicians Guide is intended for automotive technicians that are familiar with the operation of an automatic transaxle or transmission. Technicians or other persons not having automatic transaxle or transmission know-how may find this publication somewhat technically complex if additional instruction is not provided. Since the intent of this book is to explain the fundamental mechanical, hydraulic and electrical operating principles, technical terms used herein are specific to the transmission industry. However, words commonly associated with the specific transaxle or transmission function have been defined in a Glossary rather than within the text of this book. The Hydra-matic 4L80-E Technicians Guide is also intended to assist technicians during the service, diagnosis and repair of this transmission. However, this book is not intended to be a substitute for other General Motors service publications that are normally used on the job. Since there is a wide range of repair procedures and technical specifications specific to certain vehicles and transmission models, the proper service publication must be referred to when servicing the Hydra-matic 4L80-E transmission.

COPYRIGHT 1998 POWERTRAIN GROUP General Motors Corporation ALL RIGHTS RESERVED

All information contained in this book is based on the latest data available at the time of publication approval. The right is reserved to make product or publication changes, at any time, without notice. No part of any GM Powertrain publication may be reproduced, stored in any retrieval system or transmitted in any form or by any means, including but not limited to electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of Powertrain Group of General Motors Corporation. This includes all text, illustrations, tables and charts.

1

INTRODUCTIONThe Hydra-matic 4L80-E Technicians Guide is another Powertrain publication from the Technicians Guide series of books. The purpose of this publication, as is the case with other Technicians Guides, is to provide complete information on the theoretical operating characteristics of this transmission. Operational theories of the mechanical, hydraulic and electrical components are presented in a sequential and functional order to better explain their operation as part of the system. In the first section of this book entitled Principles of Operation, exacting explanations of the major components and their functions are presented. In every situation possible, text describes component operation during the apply and release cycle as well as situations where it has no effect at all. The descriptive text is then supported by numerous graphic illustrations to further emphasize the operational theories presented. The second major section entitled Power Flow, blends the information presented in the Principles of Operation section into the complete transmission assembly. The transfer of torque from the engine through the transmission is graphically displayed on a full page while a narrative description is provided on a facing half page. The opposite side of the half page contains the narrative description of the hydraulic fluid as it applies components or shifts valves in the system. Facing this partial page is a hydraulic schematic that shows the position of valves, checkballs, etc., as they function in a specific gear range. The third major section of this book displays the Complete Hydraulic Circuit for specific gear ranges. Fold-out pages containing fluid flow schematics and two dimensional illustrations of major components graphically display hydraulic circuits. This information is extremely useful when tracing fluid circuits for learning or diagnosis purposes. The Appendix section of this book provides additional transmission information regarding lubrication circuits, seal locations, illustrated parts lists and more. Although this information is available in current model year Service Manuals, its inclusion provides for a quick reference guide that is useful to the technician. Production of the Hydra-matic 4L80-E Technicians Guide was made possible through the combined efforts of many staff areas within the General Motors Powertrain Division. As a result, the Hydra-matic 4L80-E Technicians Guide was written to provide the user with the most current, concise and usable information available regarding this product.

3

HOW TO USE THIS BOOKFirst time users of this book may find the page layout a little unusual or perhaps confusing. However, with a minimal amount of exposure to this format its usefulness becomes more obvious. If you are unfamiliar with this publication, the following guidelines are helpful in understanding the functional intent for the various page layouts: Read the following section, Understanding the Graphics to know how the graphic illustrations are used, particularly as they relate to the mechanical power flow and hydraulic controls (see Understanding the Graphics page 6). Unfold the cutaway illustration of the Hydramatic 4L80-E (page 8) and refer to it as you progress through each major section. This cutaway provides a quick reference of component location inside the transmission assembly and their relationship to other components. The Principles of Operation section (beginning on page 9A) presents information regarding the major apply components and hydraulic control components used in this transmission. This section describes how specific components work and interfaces with the sections that follow. The Power Flow section (beginning on page 47) presents the mechanical and hydraulic functions corresponding to specific gear ranges. This section builds on the information presented in the Principles of Operation section by showing specific fluid circuits that enable the mechanical components to operate. The mechanical power flow is graphically displayed on a full size page and is followed by a half page of descriptive text. The opposite side of the half page contains the narrative description of the hydraulic fluid as it applies components or moves valves in the system. Facing this partial page is a hydraulic schematic which shows the position of valves, ball check valves, etc., as they function in a specific gear range. Also, located at the bottom of each half page is a reference to the Complete Hydraulic Circuit section that follows. The Complete Hydraulic Circuits section (beginning on page 75) details the entire hydraulic system. This is accomplished by using a fold-out circuit schematic with a facing page two dimensional fold-out drawing of each component. The circuit schematics and component drawings display only the fluid passages for that specific operating range. Finally, the Appendix section contains a schematic of the lubrication flow through the transmission, disassembled view parts lists and transmission specifications. This information has been included to provide the user with convenient reference information published in the appropriate vehicle Service Manuals. Since component parts lists and specifications may change over time, this information should be verified with Service Manual information.

4

HOW TO USE THIS BOOKLARGE CUTAWAY VIEW OF TRANSAXLE (FOLDOUT) HALF PAGE TEXT FOR EASY REFERENCE TO BOTH PAGES RANGE REFERENCE CHART

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HYDRA-MATIC 4L80-EOIL PUMP ASSEMBLY (4) OVERDRIVE ROLLER CLUTCH ASSEMBLY (512) FOURTH CLUTCH ASSEMBLY (523533) OVERRUN CLUTCH ASSEMBLY (504511) OVERDRIVE CARRIER ASSEMBLY (514) FORWARD CLUTCH ASSEMBLY (601616) DIRECT CLUTCH ASSEMBLY (616623) INTERMEDIATE CLUTCH ASSEMBLY (629640) INTERMEDIATE LOW SPRAG ROLLER CLUTCH CLUTCH ASSEMBLY ASSEMBLY (624) (644) REACTION CARRIER ASSEMBLY (651) REAR INTERNAL GEAR (666) OUTPUT CARRIER ASSEMBLY (661)1 POWER FROM TORQUE CONVERTER (1) 2c 2d OVERDRIVE OVERDRIVE ROLLER CARRIER CLUTCH PINION GEARS (512) (518) HOLDING HELD 3 OVERDRIVE INTERNAL GEAR DRIVEN

PARK(Engine Running)4 POWERFLOW TERMINATED

PARK(Engine Running)

4

MANUAL 2-1 BAND SERVO (5560)

FBA

STATOR ROLLER CLUTCH ASSEMBLY

PRND43

DRIVE

PRN

FILTERED ACTUATOR FEED

EX

EX

PRND4

PRN

PRND4 PRND43

REVERSE

LINE

D321 D 21 LO

HELD

PRND43

TURBINE SHAFT (502)

LINE

2LO

ACTR FD

REV

PRESSURE TAP (24)

REV EX 2-3 DRIVE DRIVE

1-2 SIGNAL

OUTPUT SHAFT (671)

PRESSURE REG

LINE

CONV FD

PRN

REVERSE

LINE

BOOST

2-3 SIGNAL

LINE (from Pump)

SUN GEAR (650)

TORQUE SIG

ACTUATOR FEED

CONVERTER HUB OUTPUT SHAFT ASSEMBLY (671) HELD

EX EX

EX

EX

LINE

SUN GEAR SHAFT (649) TURBINE SHAFT (502) LOW AND REVERSE BAND ASSEMBLY (657) PRESSURE CONTROL SOLENOID (320) MANUAL SHIFT SHAFT DETENT LEVER ASSEMBLY (711)Figure 6

FORWARD CLUTCH HOUSING (602)

PRN

LINE

SIGNAL

ACTUATOR FEED

TORQUE

PRESSURE PLATE ASSEMBLY

CONVERTER TURBINE ASSEMBLY

CONVERTER STATOR ASSEMBLY

OIL PAN (28)

FILTER ASSEMBLY (31)

MANUAL SHIFT SHAFT (708)

INPUT SPEED SENSOR ASSEMBLY (22)

MANUAL 2-1 BAND ASSEMBLY (628)

CONTROL VALVE ASSEMBLY (44)

PARKING PAWL ACTUATOR ASSEMBLY (710)

MAIN SHAFT (662)

OVERDRIVE INTERNAL GEAR DRIVEN PARKING PAWL ACTUATOR ASSEMBLY (710)

PARKING PAWL (703) ENGAGED PARKING PAWL RETURN SPRING (705)

50

CO MP LE TE HY DR PA AULI GE B C 76 CIR CU IT

FILTERED ACTR FD

FILTER (302)

4TH CL FD

PRN

3-4 SHIFT

EX

PRESSURE CONTROL SOLENOID VALVE (320)

54TH CLUTCH ORIFICED EX

1-2 SIG

15

8

50

Figure 46

Figure 47

PAGE NUMBER FOR REFERENCE TO FLUID FLOW SCHEMATIC

FLUID FLOW SCHEMATIC (FOLDOUT)RK g) PA nnin Ru

FLUID FLOW THROUGH COMPONENTS (FOLDOUT)

PARK

(Engine Running)TORQUE CONVERTER (1)

OVERRUN CLUTCH ASSEMBLY (504511)

4TH CLUTCH ASSEMBLY (523533)

FORWARD CLUTCH ASSEMBLY (602616)

DIRECT CLUTCH ASSEMBLY (616623)

2

45 8

8

9

9

8

12 9

12

10 8

APPLY/RETURN

DRIVEOVERRUN CLUTCH

DRIVE

REVERSE

49

12

12

29

49

11

19

3RD/REVERSE

11

11

45

CENTER LUBE

RELEASE

1

3RD/REV

DRIVE

CENT

ER

LUBE

REVERSE

43

47

2

30

30

2

43

45

14

47

29

CENTER LUBE ACCUM

40

2ND CL

2ND CL

2-3 DRIVE 4TH CLUTCHACCUMULATOR GASKET (47) ACCUMULATOR HOUSING (51)

2-3 DRIVE ACCUMULATOR3RD/REVERSE

2-3 DRIVE FRONT BAND APPLYACCUM 3RD CL FD ACCUMULATOR

3

2

19

43

14

43

2

3

CENTER LUBE

REVERSE

EX

ACCUM

ACCUMULATOR

FBA

4TH ACCUMULATOR

4TH CL

3RD ACCUMULATOR

ACCUM

4TH CL 3RD CL

PRND43

REAR BAND APPLY

CENTER LUBE ORIFICE CUP PLUG (208)

#626c

#526f

#10

#833a

#3

#226j

1

#3 41a 16a 41 42 #4 5 14a

42c

1

2ND ACCUM

2ND CLUTCH

4TH CLUTCH

16a

FBA 31d

37c

37d

31c

31b

FRONT LUBE

CASE (7)

RELEASE

EX

EX

PRN D 21 D 21 D 21

COEX

NV

4TH CL FD 4TH CL

LIM

3RD CL

4TH CLUTCH FEED

EX

2-3 DRIVE

26b

EX

45a 43h

19 2 3

19 2 3 25 40 42

37 2

42 18 33 36 31 45 33

19 24 35

44

50

37a/19 2c

FILTERED 2-3 DRIVE

COOLER

TORQUE SIGNAL

DRIVE

FRONT BAND APPLY

LINE

5d

18b 36b 23a

LO

PRND4

PRESSURE REG

2-3 SIGNAL

D21

RBA

D 21

REV

1-2 SIGNAL

EX

PUMP ASSEMBLY (4)

26

#6

26 17

6

REG CONV FD

30a

CONV CLUTCH SHIFT

TCC SIGNAL EXEX

49

TCC SIGNAL

18 24a 22 19 43d 5b

EX

45 4

46b

TCC SIGNAL

PRN

REL8

24

LINE

ACTR FD

BOOST

3 3b 4 2c 14a 2

REV EX

FILT ACTR FD

2ND CLUTCH

LINE

TCC SIGNAL

ACTR FD

PRND43

DRIVE

PUMP BODY (203)

REVERSE TORQUE SIG

TORQUE SIGNAL

1-2 SOL EX N.O. ON

)8(

14b

FILTERED ACTR FD EX FILTERED ACTR FD ACTUATOR FD

PRN

TORQUE SIGNAL LINE

LINE

2b

D 21

ACTUATOR FEED

EX

5c 20a

EX

DRIVE

CASE (7)

REVERSE

TCC SIGNAL

PRND43

REAR LUBE

LO

PRND4

RBA

DRIVE

REVERSE

PUMP COVER (206)

20e 2d

1

LO

LINE LO

42b

76

Figure 74

HALF PAGE TEXT AND LEGEND

PRESSURES INTAKE & DECREASE (SUCTION) CONVERTER & LUBE MAINLINE SOLENOID SIGNAL "ON" SOLENOID SIGNAL "OFF" ACCUMULATOR ACTUATOR FEED TORQUE SIGNAL

PRND4

18a

DRIVE

SUCTION

ACTUATOR FEED

DRIVECONTROL VALVE BODY (44) GASKET (45)44a 40 40 40a 39d 43a 19b 39e 42d 39c 42c

DRIVE


REVERSE

LO

PRESSURE TAP (24)

5a

139b 39a

23

OVERRUN CLUTCH LINE

#1

D321

D321

REAR BAND APPLY ACTUATOR FEED

ACTUATOR FEED REVERSE DRIVE

OIL PAN (28)

LINE

20f

FRONT OIL COOLER PIPE CONNECTOR (8)

PRND4 PRND43

LINE

PRND4

LO

REVERSE OVERRUN CLUTCH DRIVE

REVERSE

21 19d 24 22

D321

DRIVE

LO

P

RND

D

FILTER (317)

2

REGULATED APPLY

MANUAL VALVE

TCC SIGNAL

FILTERED ACTUATOR FEED DRIVE

20b

2ND CL40

19c

DRIVE

PRND43REV

LUBE PIPE (39)

#7 RBA REV

LO ALL PRND43 SWITCHES N.O. PRND4

TFP SWITCHDRIVE

LO

SPACER PLATE (46) GASKET (48) CASE (7)

REVERSE DRIVE


FILTER (302)

1-2 SHIFT VALVE

RR

U

N16

REV ACTR FD

1-2 SIGNAL

N

CL U TC H

Figure 1

21

20c

1-2 SIGNAL

ACTR FD

REG APPLY

APP/RET

REGULATED APPLY ORIFICED REG APPLY

2-3 SIG

2-3 DRIVE

20

CC

LINE

REVERSE

43c

COOLER

EX

3a

OFF

R CONV FD

TCC REG

ACTUATOR FEED

REV REV REV

47 47

34 47

38a

47

244

43b

47

18 #7

(317)

U

M

12

ACCUMULATOR HOUSING (51)

CASE (7) (Control Valve Body Side)

13

(90)41 39

2

42

44

SPACER PLATE (46)41 39 39 42 16 5 20 14 20 20 19 24 42 20 19 2 2 14 5 43 19 40 37 4 34 36 3 37 43 43 30 25 26 5 6 40 38 32 26 17 14 14 38 47 32 37 34 46 45 34 37 39 18 20 20 2 22 43 43 19 41 41

2

42

44

CONTROL VALVE BODY (44) (Case Side)42 41

16 14 14 19 37 39 2 37 3 3 25 30 26 26 34 37 26 38 47 32 26 26 17 31 26 28 5 37 5 40 26 45 34 45 31 34 33 36 37 39 18 20 5 43 20 2 22 43 42 18 36 31 23 35 45 31 23 24 33 45 5 43 22

39 5 43 43 42 18 36 31 24 24 31 34 35 43 43 45 31 23 46 33 22 19

5 43 43

20 20 21 22

2

19

42

NOTE: INDICATES BOLT HOLES - NON FUNCTIONAL HOLES HAVE BEEN REMOVED FROM COMPONENT DRAWINGS TO SIMPLIFY TRACING FLUID FLOW. - DUAL PURPOSE PASSAGES HAVE CASE SIDE NUMBERS LISTED FIRST - EXHAUST FLUID NOT SHOWN

27

28 28 26

14 14

GASKET (47) (Accumulator Housing to Spacer Plate)

GASKET (48) (Case to Spacer Plate)

GASKET (45) (Spacer Plate to Control Valve Body)

Figure 75

FOLDOUT 77

COMPLETE ILLUSTRATED PARTS LIST

25a

TCC (PWM) SOLENOID VALVE EX (323)

FBA ORIFICED EX

20d

ACTUATOR FEED

CONV FD

FILTERED 2-3 DRIVE

EX

N.O. OFF

2ND CLUTCH

12

47

26j/2814

LINE

45b

EX ORIFICED EX

LINE

2-3 SHIFT VALVE

EX

24b

23

#445

28

14d

37f

34a

28a

14

2-3 SOL

28

SUCTION

2a

LINE

17

26d/38

26a/27

8

26f/32

2-3 SIGNAL

14

37

37

34 45 26 14c 32a 26h

22b 17 24c 23

EX EX

EX

30

30

#5

24

26c/38

26e/329

31d

34c 16

43h 47

47 20

45

26g

5 20

22 47 2 43 18 16 43 41 17 42 43

45 43 23

19 22

21 21 43 5 20

17a

(39)47

26i/28

39

(302)

42 41 45 47 47

43 19

LINE

PRND4

CONVERTER FEED

ORIFICE CUP PLUG (236)

ACT FD LIMIT

4TH CLUTCH FEED 2-3 DRIVE 3RD CLUTCH FEED 2-3 SIGNAL

40

AL E GN AS RN C SI LE TC RE RETUE Y/ IV LUBE PL AP DR ONT FR

23 40

24 34 45 31 34

44 43 #9

25a 30a

5d

TC

OVERRUN CLUTCH

5 5e 6

2-3 SIGNAL PRND4

(75)

C EN

AB

AIR BLEED (210)

42a

LO ORIFICED ACTUATOR FEED ACTUATOR FEED

PRN

#11 ACTR FD

1-2 SIGNAL

LE

ACCUM

3-4 SHIFT

PRND43

43g 16 43f 22a

42a 3a5

3 37 5

10

37 23

37d 37e 45a 34b15

5e/6

37c 40a

26b

DRIVE

6

31b 12

31a

33c 23a 23/24c 24a

26a

27

#9

2a

39b/40 18a 33a/34 37b 3b/4 11 3 33b/34 36a

REG

CON V FD CON V FD

IT

7 37a 19

4TH ACCUM TORQUE SIG

3RD ACCUM 4TH CLUTCH

14 43

4TH CL FD 3RD CL ORIF EX 3RD CL FD 3RD/REV REV ORIFICED EX

36a 46a 15 45

EX

19a

DRIVE ACCUMULATOR ORIFICED ACCUM

MANUAL 2-1 BAND SERVO (5560)

43e


14d

31a

41a

37b

37e

34b

34a

26g

26h

35a

28a

14c

34c

33c

37f

FILTER (75)

41 39d

26d

26e

16b

33b

26i

17a

838 38

932 32

10

1134 34

12

1328 28

14

47

39 16 5 39

41

47

LOW & REVERSE BAND SERVO (6174)

16

14 14 43

20

2

5 43 39

22

REAR OIL COOLER PIPE CONNECTOR (90)

PUMP BODY (203) (Pump Cover Side)#1

PUMP COVER (206) (Pump Body Side)(24)

PUMP COVER (206) (Case Side)

COOL

14

2

ER

COOLER

47

45

29

3

2

45

14

47

30 4030 40

29

43

47

2

3

47 43

19

3

19 43

14

30

2

1

#10

#8

2

42

44

43 22 43

20 20

3

3

1

1

1

;;2d 44a23

20f 14b

20e 5a 19a

2b 43a 39a/40 39c1

16b/41 22a

5b 43c 43b 42b 18b 45b4

2

(39)

7

36b

31c 23/24b 17 18

46a/45

FRONT LUBE

7

8

24

7

1

10

13

40

49

42d 2 14 39e 22b 5c 47 43d13

47 14 47 27 42 30 47 47 25 26 19 14 3819

20a 20b 20d/22

19b

43e 20c/2122

20

46b/4521

19c 24/19d

14 35a 43f

43g

1

2

2

9

12

2

10

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2

48

INTERMEDIATE CLUTCH ASSEMBLY & CENTER SUPPORT (629640)

;;;; ;;;; ;;;; ;;48 47 7 47

48

;; ; ;;;; ;; ;;; ;;(208) (237) (236) (210)48 7

48

(239)4845

7 8

8

45

2

2

45

48

(8)

2

49

;; ;;;45 12

47

12

;

12

13

(90)

30

40

3

CASE (7) (Pump Cover Side)

47 38

47

47 37 34 32 16 45 5 2 6 40 37 42 36 45 2 47 19 47 47 40 39 3 2 4 34 41 18 5 17 18 30 25 45 37 36 26 17 47 47

47

;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;;

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e gin (En

PARK

(Engine Running)

;;; ;;; ;; ; ;;;;;; ;;; ;;; ; ;;; ;; ;;;;;; ;;; ;; ; ;;;;;;;; ;;;;;;;; ;; ;; ;; ;;;; ;;

;;; ;; ;;; ;; ;;;;; ;; ;; ;; ;;;;; ;; ;;;;; ; ;;;;; ;; ;;; ; ; ;;; ; ;;;; ;

(9)

;1 147 26 47 47 28 47 47 35 #11 5 24 31 45 36 42 31 23 33 43 46 5 19 22 22

2

19

43

14

32

47 47 43

47

46

21

34

OUTPUT CARRIER ASSEMBLY (661) HELD

TORQUE SIGNAL

TORQUE SIGNAL

4TH CL FD EX FBA

PRN

PRN

TORQUE CONVERTER ASSEMBLY (1)

ACT FD LIMIT

PRND4

2-3 SOL

2-3 SHIFT VALVE3RD CLUTCH FEED

EX

N.O. OFF

3

EX

1-2 SIGNAL

5

ORIFICED EX

ORIFICED ACTUATOR FEED

2-3 DRIVE

2-3 SIGNAL

ACTUATOR FEED

PARKING PAWL (703)

CASE ASSEMBLY (7)

OUTPUT SPEED SENSOR ASSEMBLY (22)


OVERDRIVE CARRIER OVERDRIVE ASSEMBLY (514) ROLLER CLUTCH (512) HOLDING

LINE SUCTION

PRND4

EX


PUMP ASSEMBLY (4)

OVERRUN CLUTCH HOUSING (504)

OVERDRIVE CARRIER OVERDRIVE PINION GEARS TURBINE SUN HELD SHAFT GEAR (502)

1

AIR BLEED (210)

PRND43

D

2

REAR LUBE

P

RND

FILTER (317)

LUBE PIPE (39)

ACTUATOR FEED

MANUAL VALVE

32

CONVERTER PUMP ASSEMBLY

CASE EXTENSION (19)

NO POWER TRANSMITTED TO DIFFERENTIAL ASSEMBLY

1

ACTR FD

REV PRND4

FILTERED ACTUATOR FEED

20

1-2 SOL EX N.O. ON

1-2 SHIFT VALVE LO ALL PRND43 SWITCHES N.O.

1-2 SIGNAL REVERSE 2-3 SIGNAL

TFP SWITCHDRIVE

REV DRIVE

ACTUATOR FEED 19

PRND4

4

51

TC C EN L AB

50

TC C EN AB LE

4TH33

34

A35

O

VO

E

37

VER38

RU

D2

3-

2

SI

GN

AL

5

UNDERSTANDING THE GRAPHICSCASE ASSEMBLY (7) MANUAL 2-1 BAND SERVO ASSEMBLY (55-60) LOW AND REVERSE BAND SERVO ASSEMBLY (61-74)


3RD AND 4TH CLUTCH ACCUMULATOR HOUSING OIL PUMP (51) ASSEMBLY (4) ACCUMULATOR HOUSING GASKET (47) CONTROL VALVE BODY SPACER PLATE (46) CONTROL VALVE ASSEMBLY (44)

CONTROL VALVE BODY SPACER PLATE GASKET (48) CONTROL VALVE BODY GASKET (45) TRANSMISSION FLUID PRESSURE MANUAL VALVE POSITION SWITCH (40)

LUBE OIL PIPE (39)

OIL FILTER ASSEMBLY (31)

OIL PAN (28)

Figure 2

The flow of transmission fluid starts in the bottom pan and is drawn through the filter, case assembly and into the oil pump assembly. This is a basic concept of fluid flow that can be understood by reviewing the illustrations provided in Figure 2. However, fluid may pass between the control valve body, spacer plate, case and other components many times before reaching a valve or applying a clutch. For this reason, the graphics are designed to show the exact location where fluid passes through a component and into other passages for specific gear range operation. To provide a better understanding of fluid flow in the Hydra-matic 4L80-E transmission, the components involved with hydraulic control and fluid flow are illustrated in three major formats. Figure 3 provides an example of these formats which are: 6

A graphic schematic representation that displays valves, ball check valves, orifices and so forth, required for the proper function of transmission in a specific gear range. In the schematic drawings, fluid circuits are represented by straight lines and orifices are represented by indentations in a circuit. All circuits are labeled and color coded to provide reference points between the schematic drawing and the two dimensional line drawing of the components. Figure 4 (page 7B) provides an illustration of a typical valve, bushing and valve train components. A brief description of valve operation is also provided to support the illustration. Figure 5 (page 7B) provides a color coded chart that references different fluid pressures used to operate the hydraulic control systems. A brief description of how fluid pressures affect valve operation is also provided.

A three dimensional line drawing of the component for easier part identification. A two dimensional line drawing of the component to indicate fluid passages and orifices.

TORQUE CONVERTER (1)

3RD/REV

DRIVE

REVERSE

E LUB TER CEN

OVERRUN CLUTCH

CENTER LUBE

RELEASE

COO

LER

COOLER

2-3 DRIVE ACCUM 4TH CLUTCHACCUMULATOR GASKET (47) ACCUMULATOR HOUSING (51)

2-3 DRIVE ACCUMULATOR FRONT BAND APPLY

2-3 DRIVE

2ND CL

2ND CL

ACCUM

ACCUMULATOR

4TH CL 3RD CL

FBA

4TH ACCUMULATOR

4TH CL

3RD ACCUMULATOR

3RD CL FD

EX

ACCUMULATOR

3RD/REVERSE

REVERSE

ACCUM

ACCUM

REAR OIL COOLER PIPE CONNECTOR (90)

CENTER LUBE

2ND ACCUM

4TH CLUTCH

17a

8

9

10

11

12

13

14

FRONT LUBE

CASE (7)

RELEASE

EX

EX

EXNA

FILTERED 2-3 DRIVE

COOLER

DRIVE

LINE

5d

18b 36b 22b 17 23 23 18 24a 22 19 20d 23a

LO

PRND4

PRESSURE REG

EX EX

D21

D 21

REG CONV FD

CONV CLUTCH SHIFT

LINE

49

TCC SIGNAL

LINE

45b

EX

TCC SIGNAL

PRN

EX

LINE

ACTR FD

BOOST

3 3b 4 2c 14a 2

REV EX

FILT ACTR FD

LINE

TCC SIGNAL

DRIVE

TORQUE SIG TORQUE SIGNAL LINE

14b

FILTERED ACTR FD EX FILTERED ACTR FD ACTUATOR FD

PRN

ACTUATOR FEED

D 21

LINE

2b

EX

EX

5c 20a 20b 21

DRIVE

CASE (7)

REVERSE

TCC SIGNAL

PRND43

LO

20e 2d

REAR

LO

LINE LO

#7 RBA REV

PRND4

REVERSE DRIVE

REVERSE DRIVE

GRAPHIC SCHEMATIC REPRESENTATION

OIL PUMP BODY (4)

ACCUMULATOR ACCUMULATOR HOUSING (51)

THREE DIMENSIONAL PUMP COVER SIDE THREE DIMENSIONAL CASE SIDE

TWO DIMENSIONAL TWO DIMENSIONAL TWO DIMENSIONAL

Figure 3

PRESSURES INTAKE & DECREASE (SUCTION) CONVERTER & LUBE MAINLINE SOLENOID SIGNAL "ON" SOLENOID SIGNAL "OFF" ACCUMULATOR ACTUATOR FEED TORQUE SIGNAL

SUCTION

DRIVE

40a

39d

43a

19b

39e

42d

39c

OVERRUN CLUTCH LINE

#1

LO

PRESSURE TAP (24)

1

42c


REVERSE

CONTROL VALVE BODY (44) GASKET (45)

23

SPACER PLATE (46) GASKET (48) CASE (7)

ACTUATOR FEED

DRIVE40 40 44a

5a

39a

39b

PRND4

18a

DRIVE

D321

D321

ACTUATOR FEED

ACTUATOR FEED

OIL PAN (28)

LINE

42b

LO

DRIVE

REVERSE

REV

LO ALL PRND43 SWITCHES N.O.

DRIVE

PUMP COVER (206)

LUBE PIPE (39)

TFP SWITCH

RBA

1

PRND43

PRND4

20f

DRIVE

D

2

LUBE

FRONT OIL COOLER PIPE CONNECTOR (8)

PRND4 PRND43

LINE

PRND4

LO

REVERSE OVERRUN CLUTCH

REVERSE

19d

24 22

2ND CL

D321

DRIVE

LO

P

RND

FILTER (317)

19c

DRIVE

REGULATED APPLY

MANUAL VALVE

TCC SIGNAL

FILTERED ACTUATOR FEED DRIVE

REAR BAND APPLY

FOLDOUT 7

REV ACTR FD

1-2 SIGNAL


FILTER (302)

1-2 SHIFT VALVE

EX N.O. ON

ACTR FD

PRND43

PUMP BODY (203)

REVERSE

TORQUE SIGNAL

1-2 SOL

21

20c

1-2 SIGNAL

2ND CLUTCH

ACTR FD

REG APPLY

2-3 DRIVE

20

APP/RET

REGULATED APPLY ORIFICED REG APPLY

2-3 SIG

LINE

REVERSE

43c

COOLER

EX

3a

OFF

R CONV FD

TCC REG

ACTUATOR FEED

25a

TCC (PWM) SOLENOID VALVE EX (323)

ACTUATOR FEED

8

REL

24

FBA ORIFICED EX

43d 5b 43b

CONV FD

4

FILTERED 2-3 DRIVE

EX

45

46b

EX ORIFICED EX

2-3 SHIFT VALVEEX

EX

30a

TCC SIGNAL

2-3 SOL N.O. OFF

24b

#4 2ND CLUTCH REV REV REV

2-3 SIGNAL

SUCTION

2a

LINE

1-2 SIGNAL

REV

EX

24c

RBA

PUMP ASSEMBLY (4)

2-3 SIGNAL

EX

LINE

PRND4

CONVERTER FEED


ACT FD LIMIT

4TH CLUTCH FEED 2-3 DRIVE 3RD CLUTCH FEED 2-3 SIGNAL

AL E IGN AS URN CS LE TC RE /RET E BE Y PL RIV LU AP D ONT FR

FRONT BAND APPLY

OVERRUN CLUTCH

5 5e 6

2-3 SIGNAL PRND4

TC

CE

AIR BLEED (210)

42a

TORQUE SIGNAL

LO ORIFICED ACTUATOR FEED ACTUATOR FEED

PRN

#11 ACTR FD

1-2 SIGNAL

B

LE

DRIVE

26a 6

27

43h

#916

2-3 DRIVE

26b

EX

45a

4TH CLUTCH FEED

EX

19a

DRIVE ACCUMULATOR ORIFICED ACCUM

3RD CL

REG

CON V FD CON V FD

37a

19

4TH CL FD 4TH CL

CO NV L

PRN D 21 D 21 D 21

MANUAL 2-1 BAND SERVO (5560) 4TH CL FD

IMIT

7

4TH ACCUM TORQUE SIG

3RD ACCUM 4TH CLUTCH

LOW & REVERSE BAND SERVO (6174)36a 46a 15 45

3RD CL

ORIF EX 3RD CL FD 3RD/REV REV PRND43

ORIFICED EX

EX

2ND CLUTCH

FBA 31d


16a

37c

37d

31c

31b

43e


26g

26h

14d

34a

31a

41a

37b

37e

34b

38

38

32

32

34

34

35a

28

41

28

28a

14c

34c

33c

37f

FILTER (75)

REAR BAND APPLY

CENTER LUBE

PRND43

#626c

#526f

#10

#833a

#3

#226j

26e

16b

26d

33b

26i

;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;;

UNDERSTANDING THE GRAPHICSOVERRUN CLUTCH ASSEMBLY (504511) 4TH CLUTCH ASSEMBLY (523533) FORWARD CLUTCH ASSEMBLY (602616) DIRECT CLUTCH ASSEMBLY (616623) INTERMEDIATE CLUTCH ASSEMBLY & CENTER SUPPORT (629640)

SPACER PLATE CASE SIDEGASKET (47) GASKET (48) SPACER PLATE (46) GASKET (45)

APPLY/RETURN

FRONT LUBE

DRIVE

DRIVE

REVERSE 3RD/REVERSE

CENTER LUBE

VALVE BODY ALVE SPACER SPACER PLATE PLATE (23)

C TC L AB EN

ACCUM

3-4 SHIFT

43g 43f 22a

THREE DIMENSIONAL

TWO DIMENSIONAL

C TC A EN E BL

CASE SIDE

CONTROL VALVE BODY ALVE ASSEMBLY ASSEMBLY (44)

THREE DIMENSIONAL TWO DIMENSIONAL

CASE ASSEMBLY ASSEMBL (7)

THREE DIMENSIONAL

FOLDOUT 7A

UNDERSTANDING THE GRAPHICSTYPICAL BUSHING AND VALVE

NOTE: NOT ALL VALVES ARE USED WITH A BUSHINGSPRING VALVE BORE PLUG BALL CHECK VALVE RETAINING PIN

BUSHING

SPACER PLATE VALVE BODY

RESTRICTING ORIFICE

SPRING VALVE BORE PLUG BUSHING

BUSHING TO APPLY COMPONENT

SIGNAL FLUID

SIGNAL FLUID

EX WITH SIGNAL FLUID PRESSURE EQUAL TO OR LESS THAN SPRING AND SPRING ASSIST FLUID PRESSURE THE VALVE REMAINS IN CLOSED POSITION.

EX WITH SIGNAL FLUID PRESSURE GREATER THAN SPRING AND SPRING ASSIST FLUID PRESSURE THE VALVE MOVES OVER.

Figure 4

FLUID PRESSURESINTAKE & DECREASE (SUCTION) CONVERTER & LUBE MAINLINE SOLENOID SIGNAL ON SOLENOID SIGNAL OFF ACCUMULATOR

A

B

ACUATOR FEED TORQUE SIGNAL

EXHAUST DIRECTION OF FLOW

WITH EQUAL SURFACE AREAS ON EACH END OF THE VALVE, BUT FLUID PRESSURE "A" BEING GREATER THAN FLUID PRESSURE "B", THE VALVE WILL MOVE TO THE RIGHT.

Figure 5

SPACER PLATE

SPACER PLATE

EXHAUST FROM THE APPLY COMPONENT UNSEATS THE BALL CHECK VALVE, THEREFORE CREATING A QUICK RELEASE.

SPRING APPLY ASSIST FLUID FLUID

APPLY FLUID

SPRING ASSIST FLUID

APPLY FLUID SEATS THE BALL CHECK VALVE FORCING FLUID THROUGH AN ORIFICE IN THE SPACER PLATE, WHICH CREATES A SLOWER APPLY.

A

B

WITH THE SAME FLUID PRESSURE ACTING ON BOTH SURFACE "A" AND SURFACE "B" THE VALVE WILL MOVE TO THE LEFT. THIS IS DUE TO THE LARGER SURFACE AREA OF "A" THAN "B".

RETAINING PIN

VALVE BODY

7B

HYDRA-MATIC 4L80-EOIL PUMP ASSEMBLY (4) OVERDRIVE ROLLER CLUTCH ASSEMBLY (512) FOURTH CLUTCH ASSEMBLY (523533) OVERRUN CLUTCH ASSEMBLY (504511) OVERDRIVE CARRIER ASSEMBLY (514) FORWARD CLUTCH ASSEMBLY (601616) DIRECT CLUTCH ASSEMBLY (616623) INTERMEDIATE CLUTCH ASSEMBLY (629640) INTERMEDIATE LOW SPRAG ROLLER CLUTCH CLUTCH ASSEMBLY ASSEMBLY (624) (644) REACTION CARRIER ASSEMBLY (651) REAR INTERNAL GEAR (666) OUTPUT CARRIER ASSEMBLY (661)

CONVERTER PUMP ASSEMBLY

CASE EXTENSION (19)

STATOR ROLLER CLUTCH ASSEMBLY

OUTPUT SHAFT (671)

CASE ASSEMBLY (7)

OUTPUT SPEED SENSOR ASSEMBLY (22)

PARKING PAWL (703) TORQUE CONVERTER ASSEMBLY (1)

SUN GEAR (650)

SUN GEAR SHAFT (649) TURBINE SHAFT (502) LOW AND REVERSE BAND ASSEMBLY (657) PRESSURE CONTROL SOLENOID (320) MANUAL SHIFT SHAFT DETENT LEVER ASSEMBLY (711)Figure 6

PRESSURE PLATE ASSEMBLY

CONVERTER TURBINE ASSEMBLY

CONVERTER STATOR ASSEMBLY

OIL PAN (28)


MANUAL SHIFT SHAFT (708)

INPUT SPEED SENSOR ASSEMBLY (22)


CONTROL VALVE ASSEMBLY (44)


MAIN SHAFT (662)

8

Figure 7

HYDRA-MATIC 4L80-E CROSS SECTIONAL DRAWINGA cross sectional line drawing is typically the standard method for illustrating either an individual mechanical component or a complete transmision assembly. However, unless a person is familiar with all the individual components of the transmission, distinguishing components may be difficult in this type of drawing. For this reason, a three dimensional perspective illustration (shown on page 8) is the primary drawing used throughout this book. The purpose for this type of illustration is to provide a more exacting graphic representation of each component and to show their relationship to other components within the transmission assembly. It is also useful for8A

understanding the cross sectional line drawing by comparing the same components from the three dimensional perspective illustration. In this regard it becomes an excellent teaching instrument. Additionally, all the illustrations contained in this book use a color scheme that is consistent throughout this book. In other words, regardless of the type of illustration or drawing, all components have an assigned color and that color is used whenever that component is illustrated. This consistency not only helps to provide for easy component identification but it also enhances the graphic and color continuity between sections.

GENERAL DESCRIPTIONThe Hydra-matic 4L80-E is a fully automatic four speed rear wheel drive electronically controlled transmission. It consists primarily of a four-element torque converter, three planetary gear sets, a hydraulic pressurization and control system, friction and mechanical clutches. The four-element torque converter contains a pump, a turbine, a pressure plate splined to the turbine, and a stator assembly. The torque converter acts as a fluid coupling to smoothly transmit power from the engine to the transmission. It also hydraulically provides additional torque multiplication when required. The pressure plate, when applied, provides a mechanical direct drive coupling of the engine to the transmission. The three planetary gear sets provide the four forward gear ratios and reverse. Changing gear ratios is fully automatic and is accomplished through the use of a powertrain control module (PCM). The PCM receives and monitors various electronic sensor inputs and uses this information to shift the transmission at the optimum time. The PCM commands shift solenoid valves, within the transmission, on and off to control shift timing. The PCM also controls the apply and release of the torque converter clutch which allows the engine to deliver the maximum fuel efficiency without sacrificing vehicle performance. The hydraulic system primarily consists of a gear type pump and a control valve body. The pump maintains the working pressures needed to stroke the servos and clutch pistons that apply or release the friction components. These friction components (when applied or released) support the automatic shifting qualities of the transmission. The friction components used in this transmission consist of five multiple disc clutches and two bands. The multiple disc clutches combine with three mechanical components, two roller clutches and a sprag clutch, to deliver five different gear ratios through gear sets. The gear sets then transfer torque through the output shaft and out to the drive axles.

PRINCIPLES OF OPERATIONAn automatic transmission is the mechanical component of a vehicle that transfers power (torque) from the engine to the wheels. It accomplishes this task by providing a number of forward gear ratios that automatically change as the speed of the vehicle increases. The reason for changing forward gear ratios is to provide the performance and economy expected from vehicles manufactured today. On the performance end, a gear ratio that develops a lot of torque (through torque multiplication) is required in order to initially start a vehicle moving. Once the vehicle is in motion, less torque is required in order to maintain the vehicle at a certain speed. Once the vehicle has reached a desired speed, economy becomes the important factor and the transmission will shift into overdrive. At this point output speed is greater than input speed, and, input torque is greater than output torque. Another important function of the automatic transmission is to allow the engine to be started and run without transferring torque to the wheels. This situation occurs whenever Park (P) or Neutral (N ) range has been selected. Also, operating the vehicle in a rearward direction is possible whenever Reverse ( R ) range has been selected (accomplished by the gear sets). The variety of ranges in an automatic transmission are made possible through the interaction of numerous mechanically, hydraulically and electronically controlled components inside the transmission. At the appropriate time and sequence, these components are either applied or released and operate the gear sets at a gear ratio consistent with the drivers needs. The following pages describe the theoretical operation of the mechanical, hydraulic and electrical components found in the Hydra-matic 4L80-E transmission. When an understanding of these operating principles has been attained, diagnosis of these transmission systems is made easier.

EXPLANATION OF GEAR RANGES

P

R

N

D

D

2

1

economy. Overdrive range allows the transmission to operate in each of the four forward gear ratios. Downshifts to a lower gear, or higher gear ratio, are available for safe passing by depressing the accelerator or by manually selecting a lower gear with the shift selector. D Manual Third can be used for conditions where it may be desirable to use only three gear ratios. These conditions include towing a trailer and driving on hilly terrain. This range is also helpful for engine braking when descending slight grades. Upshifts and downshifts are the same as in Overdrive range for first, second and third gears except that the transmission will not shift into fourth gear. 2 Manual Second adds more performance for congested traffic and hilly terrain. It has the same starting ratio (first gear) as Manual Third but prevents the transmission from shifting above second gear. Thus, Manual Second can be used to retain second gear for acceleration and engine braking as desired. Manual Second can be selected at any vehicle speed but will not downshift into second gear until the vehicle speed drops below approximately 100 km/h (62 mph). 1 Manual First can be selected at any vehicle speed. If the transmission is in third or fourth gear it will immediately shift into second gear. When the vehicle speed slows to below approximately 56 km/h (35 mph) the transmission will then shift into first gear. This is particularly beneficial for maintaining maximum engine braking when descending steep grades.FOLDOUT 9

Figure 8

The transmission can be operated in any one of the seven different positions shown on the shift quadrant (Figure 8). P Park position locks the output shaft, enabling the engine to be started while preventing the vehicle from rolling either forward or backward. For safety reasons, the vehicles parking brake should be used in addition to the transmission Park position. Because the output shaft is mechanically locked by a parking pawl anchored in the case, Park position should not be selected until the vehicle has come to a complete stop. R Reverse enables the vehicle to be operated in a rearward direction. N Neutral position enables the engine to start and operate without driving the vehicle. If necessary, this position should be selected to restart the engine while the vehicle is moving. D Overdrive range should be used for all normal driving conditions for maximum efficiency and fuel

9A

MAJOR MECHANICAL COMPONENTSOVERDRIVE CARRIER ASSEMBLY (514)

4TH CLUTCH ASSEMBLY (523-533) TORQUE CONVERTER ASSEMBLY (1) PUMP ASSEMBLY (4)SPLINED TOGETHER

OVERRUN CLUTCH ASSEMBLY (504-511)

OVERDRIVE ROLLER CLUTCH (512) TURBINE SHAFT (502)

TURBINE SHAFT (502)

SPLINED TOGETHER

FORWARD CLUTCH ASSEMBLY (601-614)

DIRECT CLUTCH HUB (615)

OUTPUT CARRIER ASSEMBLY (661) LOW AND REVERSE BAND ASSEMBLY (657)

SPLINED TOGETHER

TRANSMISSION CASE INTERMEDIATE (7) CLUTCH ASSEMBLY (629-638) INTERMEDIATE SPRAG CLUTCH OUTERRACE (625)

REACTION CARRIER ASSEMBLY (651)

SUN GEAR (650)

PARKING PAWL (703)

DIRECT CLUTCH ASSEMBLY (616-623)



FORWARD CLUTCH HUB (613)

MAIN SHAFT (662) INTERMEDIATE SPRAG CLUTCH ASSEMBLY (624) SUN GEAR SHAFT (649)SPLINED TOGETHER

CENTER SUPPORT ASSEMBLY (640)

LOW ROLLER CLUTCH ASSEMBLY (644)

LOW AND REVERSE BAND SERVO ASSEMBLY (61-74)

MANUAL 2-1 BAND SERVO ASSEMBLY (55-60)

MAIN SHAFT (662) REAR INTERNAL GEAR (666)

OUTPUT SHAFT ASSEMBLY (671)

SPLINED INTO OUTPUT CARRIER ASSEMBLY (661)

10

Figure 9

COLOR LEGENDMAJOR MECHANICAL COMPONENTS

The foldout graphic on page 10 contains a disassembled drawing of the major components used in the Hydra-matic 4L80-E transmission. This drawing, along with the cross sectional illustrations on page 8 and 8A, show the major mechanical components and their relationship to each other as a complete assembly. Therefore, color has been used throughout this book to help identify parts that are splined together, rotating at engine speed, held stationary, and so forth. Color differentiation is particularly helpful when using the Power Flow section for understanding the transmission operation. The color legend below provides the general guidelines that were followed in assigning specific colors to the major components. However, due to the complexity of this transmission, some colors (such as grey) were used for artistic purposes rather than based on the specific function or location of that component. Components held stationary in the case or splined to the case. Examples: Pump Assembly (4), 4th Clutch Housing (529) and Manual 2-1 Band Assembly (628). Also includes Roller Clutches and Sprag assemblies. Components that rotate at engine speed. Examples: Torque Converter Assembly (1) and Oil Pump Drive (205) and Driven (204) Gears. Components that rotate at turbine speed. Examples: Converter Turbine, Turbine Shaft (502) and Overdrive Carrier Assembly (514). Components that rotate at transmission output speed. Examples: Output Shaft Assembly (671) and Output Carrier Assembly (661). Components such as the Stator in the Torque Converter (1), Overrun Clutch Housing Assembly (504), and Reaction Carrier Assembly (651). Components such as the Forward Clutch Housing Assembly (602). Forward Clutch Hub (613), Main shaft (662) and Rear Internal Gear (666). Components such as the Direct Clutch Housing (623) and Intermediate Clutch Sprag Outer Race (625). Accumulators, Servos and Bands. All bearings and bushings. All seals

10A

COLOR LEGENDAPPLY COMPONENTS

The Range Reference Chart on page 11, provides another valuable source of information for explaining the overall function of the Hydra-matic 4L80-E transmission. This chart highlights the major apply components that function in a selected gear range, and the specific gear operation within that gear range. Included as part of this chart is the same color reference to each major component that was previously discussed. If a component is active in a specific gear range, a word describing its activity will be listed in the column below that component. The row where the activity occurs corresponds to the appropriate transmission range and gear operation. An abbreviated version of this chart can also be found at the top of the half page of text located in the Power Flow section. This provides for a quick reference when reviewing the mechanical power flow information contained in that section.

10B

RANGE REFERENCE CHARTHYDRAMATIC 4L80-E - GEAR RATIOS FIRST 2.48 FOURTH .75 SECOND 1.48 REVERSE 2.08 THIRD 1.00

RANGE

GEAR

1-2 SHIFT 2-3 SHIFT SOLENOID SOLENOID ON OFF

FOURTH CLUTCH

OVERRUN CLUTCH

OVERDRIVE ROLLER CLUTCH HOLDING

FORWARD CLUTCH

DIRECT CLUTCH

MANUAL 2-1 BAND

INTERMEDIATE SPRAG CLUTCH

INTERMEDIATE CLUTCH

LOW ROLLER CLUTCH

LOW AND REVERSE BAND

P-N R DREVERSE 1st 2nd 3rd 4th 1st

ON ON OFF OFF ON ON OFF OFF ON OFF ON OFF

OFF OFF OFF ON ON OFF OFF ON OFF OFF OFF OFF APPLIED APPLIED APPLIED APPLIED APPLIED APPLIED APPLIED APPLIED

HOLDING HOLDING HOLDING HOLDING APPLIED APPLIED

APPLIED

APPLIED

*HOLDING OVERRUNNING OVERRUNNING APPLIED APPLIED APPLIED

HOLDING OVERRUNNING OVERRUNNING OVERRUNNING HOLDING APPLIED APPLIED OVERRUNNING OVERRUNNING HOLDING APPLIED OVERRUNNING HOLDING APPLIED OVERRUNNING APPLIED

APPLIED APPLIED

OVERRUNNING APPLIED APPLIED HOLDING HOLDING HOLDING HOLDING HOLDING HOLDING HOLDING APPLIED APPLIED APPLIED APPLIED APPLIED APPLIED APPLIED APPLIED APPLIED APPLIED

*HOLDING OVERRUNNING

D 2 1

2nd 3rd 1st 2nd 1st 2nd

*HOLDING

*HOLDING

*HOLDING BUT NOT EFFECTIVEON = SOLENOID ENERGIZED OFF = SOLENOID DE-ENERGIZED

@ THE SOLENOID'S STATE FOLLOWS A SHIFT PATTERN WHICH DEPENDS UPON VEHICLE SPEED AND THROTTLE POSTION. IT DOES NOT DEPEND UPON THE SELECTED GEAR.

NOTE: DESCRIPTIONS ABOVE EXPLAIN COMPONENT FUNCTION DURING ACCELERATION.

Figure 10

11

TORQUE CONVERTERTURBINE THRUST SPACER (B) PRESSURE PLATE SPRING (E) THRUST BEARING ASSEMBLY (G) THRUST BEARING ASSEMBLY (G)

CONVERTER HOUSING COVER ASSEMBLY (A)

PRESSURE PLATE ASSEMBLY (C)

DAMPER ASSEMBLY (D)

STATOR ASSEMBLY (H) TURBINE ASSEMBLY (F) F

CONVERTER PUMP ASSEMBLY (I)

TORQUE CONVERTER:

The torque converter (1) is the primary component for transmittal of power between the engine and the transmission. It is bolted to the engine flywheel (also known as the flexplate) so that it will rotate at engine speed. Some of the major functions of the torque converter are: to provide for a smooth conversion of torque from the engine to the mechanical components of the transmission. to multiply torque from the engine that enables the vehicle to achieve additional performance when required. to mechanically operate the transmission oil pump (4) through the converter hub. to provide a mechanical link, or direct drive, from the engine to the transmission through the use of a torque converter clutch (TCC). The torque converter assembly is made up of the following five main sub-assemblies: a converter housing cover assembly (A) which is welded to the converter pump assembly (I). a converter pump assembly (I) which is the driving member. a turbine assembly (F) which is the driven or output member. a stator assembly (G) which is the reaction member located between the converter pump and turbine assemblies. a pressure plate assembly (C) splined to the turbine assembly to enable direct mechanical drive when appropriate.CONVERTER PUMP ASSEMBLY AND TURBINE ASSEMBLY

A I

D G STATOR SHAFT (235) E

B

TURBINE SHAFT (502) CONVERTER HUB

H

When the engine is running the converter pump assembly acts as a centrifugal pump by picking up fluid at its center and discharging it at its rim between the blades (see Figure 12). The force of this fluid then hits the turbine blades and causes the turbine to rotate. As the engine and converter pump increase in RPM, so does the turbine.PRESSURE PLATE, DAMPER AND CONVERTER HOUSING ASSEMBLIES

Torque converter failure could cause loss of drive

and or loss of power. To reduce torsional shock during the apply of the pressure plate to the converter cover, a spring loaded damper assembly (D) is used. The pressure plate is attached to the pivoting mechanism of the damper assembly which allows the pressure plate to rotate independently of the damper assembly up to approximately 45 degrees. During engagement, the springs in the damper assembly cushion the pressure plate engagement and also reduce irregular torque pulses from the engine or road surface. Figure 11

The pressure plate is splined to the turbine hub and applies (engages) with the converter cover to provide a mechanical coupling of the engine to the transmission. When the pressure plate assembly is applied, the amount of slippage that occurs through a fluid coupling is reduced (but not eliminated), thereby providing a more efficient transfer of engine torque to the drive wheels.

12

TORQUE CONVERTERFLUID FLOW

STATOR ASSEMBLY (H) TURBINE ASSEMBLY (F) CONVERTER PUMP ASSEMBLY (I)

Figure 12 Stator roller clutch failure roller clutch freewheels in both directions can cause poor acceleration at low speed. roller clutch locks up in both directions can cause poor acceleration at high speed. Overheated fluid.

STATOR ASSEMBLYSTATOR

CONVERTER MULTIPLYING

STATOR HELD FLUID FLOW REDIRECTED

The stator assembly is located between the pump assembly and turbine assembly, and is mounted on a one-way roller clutch. This oneway roller clutch allows the stator to rotate in one direction and prevents (holds) the stator from rotating in the other direction. The function of the stator is to redirect fluid returning from the turbine in order to assist the engine in turning the converter pump assembly. At low vehicle speeds, when greater torque is needed, fluid from the turbine hits the front side of the stator blades (the converter is multiplying torque). At this time, the one-way roller clutch prevents the stator from rotating in the same direction as the fluid flow, thereby redirecting fluid to assist the engine in turning the converter pump. In this mode, fluid leaving the converter pump has more force to turn the turbine assembly and multiply engine torque. As vehicle speed increases and less torque is required, centrifugal force acting on the fluid changes the direction of the fluid leaving the turbine such that it hits the back side of the stator blades (converter at coupling speed). When this occurs, the roller clutch overruns and allows the stator to rotate freely. Fluid is no longer being redirected to the converter pump and engine torque is not being multiplied.

FLUID FLOW FROM TURBINE

CONVERTER AT COUPLING SPEED STATOR ROTATES FREELY

Figure 13

13

TORQUE CONVERTERRELEASE APPLY

When the torque converter clutch is released, fluid is fed into the torque converter by the pump into the release fluid passage. The release fluid passage is located between the stator shaft (235) and the turbine shaft (502). Fluid travels between the shafts and enters the release side of the pressure plate at the end of the turbine shaft. The pressure plate is forced away from the converter cover and allows the torque converter turbine to rotate at speeds other than engine speed. The release fluid then flows between the friction element on the pressure plate and the converter cover to enter the apply side of the torque converter. The fluid then exits the torque converter through the apply passage, which is located between the torque converter clutch hub and the stator shaft (235), and enters the pump.

When the PCM determines that the vehicle is at the proper speed for the torque converter clutch to apply it sends a signal to the TCC (PWM) solenoid valve. The TCC (PWM) solenoid valve then regulates line fluid from the pump into the regulated apply passage. The regulated apply fluid then feeds the apply fluid passage and applies the torque converter. The apply passage is located between the turbine shaft and the stator shaft. The fluid flows between the shafts, then passes into the torque converter on the apply side of the pressure plate assembly. Release fluid is then routed out of the torque converter between the turbine shaft and the stator shaft. Apply fluid pressure forces the pressure plate against the torque converter cover to provide a mechanical link between the engine and the turbine. The TCC apply should occur in fourth gear (also third gear in some applications), and should not apply until the transmission fluid has reached a minimum operating temperature of 8C (46F) and the engine coolant temperature reaches 50C (122F). For more information on TCC apply and release, see Overdrive Range Fourth Gear TCC Released and Applied, pages 6465.

No TCC apply can be caused by:

TCC (PWM) solenoid valve assembly (323) malfunction. TCC valve (223) stuck or binding TCC regulator apply valve (324) stuck or binding Converter limit valve (214) stuck or binding TCC enable valve (217) stuck or binding Spacer plate and gaskets misaligned or incorrect Pressure plate assembly friction material worn or damaged



RELEASE FLUID

APPLY FLUID TURBINE SHAFT (502) TURBINE SHAFT (502) APPLY FLUID APPLY FLUID

RELEASE FLUID RELEASE FLUID

PRESSURE PLATE

PRESSURE PLATE

TCC RELEASE14Figure 14

TCC APPLY

APPLY COMPONENTSThe Apply Components section is designed to explain the function of the hydraulic and mechanical holding devices used in the Hydra-matic 4L80-E transmission. Some of these apply components, such as clutches and bands, are hydraulically applied and released in order to provide automatic gear range shifting. Other components, such as a roller clutch or sprag clutch, often react to a hydraulically applied component by mechanically holding or releasing another member of the transmission. This interaction between the hydraulically and mechanically applied components is then explained in detail and supported with a graphic illustration. In addition, this section shows the routing of fluid pressure to the individual components and their internal functions when it applies or releases. The sequence in which the components in this section have been discussed coincides with their physical arrangement inside the transmission. This order closely parallels the disassembly sequence used in the Hydra-matic 4L80-E Unit Repair Section located in Section 7 of the appropriate Service Manual. It also correlates with the components shown on the Range Reference Charts that are used throughout the Power Flow section of this book. The correlation of information between the sections of this book helps the user more clearly understand the hydraulic and mechanical operating principles for this transmission.

MATING OR RELATED COMPONENTS

BRIEF DESCRIPTION

FUNCTIONAL DESCRIPTION

APPLY COMPONENTS

APPLY COMPONENTS

4TH CLUTCH:

APPLIED

RELEASED

4TH CLUTCH APPLY:

To apply the 4th clutch, 4th clutch fluid is fed from the case, through the 4th clutch housing bolt (26) and behind the 4th clutch piston (528). 4th clutch fluid pressure forces the piston against the 4th clutch spring assembly (532) to cushion the apply. As fluid pressure increases, the piston compresses the clutch plates (steel and fiber) together until they are held against the 4th clutch backing plate (524). When fully applied, the steel plates (526) and fiber plates (525) are locked together and held stationary by the 4th clutch housing. The internal teeth on the fiber plates hold the overrun clutch housing (504) stationary to prevent the overdrive sun gear from rotating. The orifice cup plug (530) is pressed into the 4th lutch housing. Air in the 4th clutch fluid circuit s forced out the orifice when 4th clutch fluid ressure increases to prevent excess cushion during th clutch apply.

OVERRUN CLUTCH APPLY:

4TH CLUTCH BACKING PLATE (524)

Plugged fourth apply passage, damaged clutch plates, return spring assembly or piston seals can cause no fourth/slips in fourth.

4TH CLUTCH HOUSING (529)

SPRING RETAINER RING (533)

To apply the overrun clutch, overrun clutch fluid is fed through the oil pump hub to the inner hub of the overrun clutch housing. Feed holes in the inner hub allow fluid to enter the housing behind the overrun clutch piston (505). Overrun clutch fluid pressure seats the overrun clutch ball check valve (located in the housing) and moves the piston to compress the spring assembly (506) to cushion the apply. As fluid pressure increases, the piston compresses the clutch plates (steel and fiber) together until they are held against the overrun clutch backing plate (510). Also, the increase in fluid pressure forces any air in the overrun clutch fluid circuit to exhaust past the ball check valve, before it seats, to prevent excess cushion during clutch apply. When fully applied, the steel plates (508) and fiber plates (509) are locked together, thereby holding the overrun clutch housing and overdrive carrier together. This forces the housing and carrier to turn as one unit during engine compression braking in the Manual gear ranges.If inoperative the overrun clutch can cause loss of drive, no overrun braking - D3, No fourth gear - D4, engine stall and harsh shifts from D4 to D3, D2 or D1.505 506 507 508

SPRING ASSEMBLY (506)

OVERRUN CLUTCH APPLY FLUID

OVERRUN CLUTCH PISTON ASSEMBLY (505)

OVERRUN CLUTCH HOUSING (504) LUBE PASSAGE

BACKING PLATE 4TH CLUTCH RETAINER RING PISTON (523) (528)

4TH CLUTCH HOUSING BOLT CASE 4TH CLUTCH (26) (7) APPLY FLUID 530 532 533

523

524

525

526

528

529

20

Figure 20

Figure 21

CUTAWAY VIEW

DISASSEMBLED VIEW

Figure 15

The 4th clutch assembly, located in the 4th clutch housing (529), is held stationary to the transmission case (7) by the 4th clutch housing bolt (26). The external teeth on the reaction (steel) plates (526) are splined to the 4th clutch housing while the internal teeth on the fiber clutch plate assemblies (525) are splined to the overrun clutch housing (504). The 4th clutch is applied only when the transmission is in Fourth gear to provide an overdrive gear ratio.

4TH CLUTCH ASSEMBLY (523-533)

4TH CLUTCH RELEASE:

4TH CLUTCH APPLY FLUID PASSAGE

To release the 4th clutch, 4th clutch fluid exhausts through the 4th clut circuit, allowing pressure at the 4th clutch piston (528) to decrease. absence of fluid pressure, spring force from the spring assembly (532) the 4th clutch piston away from the clutch pack. This disengages th plates (526) and fiber plates (525) from the backing plate (524), allowing the overrun clutch housing and overdrive sun gear to rotate.FIBER STEEL CLUTCH PLATE CLUTCH ASSEMBLY PLATE (525) (526) INNER SEAL (527) 4TH CLUTCH ORIFICE (530) OUTER SEAL (531)

OVERRUN CLUTCH RELEASE:OVERRUN CLUTCH HOUSING (504)

To release the overrun clutch, overrun clutch fluid exhausts through the overrun clutch housing inner hub and into the oil pump hub, allowing pressure at the overrun clutch piston (505) to decrease. In the absence of fluid pressure, spring force from the spring assembly (506) moves the overrun clutch piston (505) away from the clutch pack. This disengages the steel plates (508) and the fiber plates (509) from the backing plate (510) and disconnects the overrun clutch housing from the overdrive carrier.OVERRUN CLUTCH BALL CHECK VALVE

During the exhaust of overrun clutch fluid, the overrun clutch ball check valve, located in the overrun clutch housing, unseats. Centrifugal force, resulting from the rotation of the overrun clutch housing, forces residual overrun clutch fluid to the outside of the piston housing and past the unseated ball check valve. If this fluid did not completely exhaust from behind the piston, there could be a partial apply, or drag, of the overrun clutch plates.

OVERRUN CLUTCH:


The overrun clutch assembly is located in the overrun clutch housing (504). The external teeth on the reaction (steel) plates (508) are splined to the overrun clutch housing while the internal teeth on the fiber clutch plate assemblies (509) are splined to the overdrive carrier assembly (514). The overrun clutch is applied only when the shift selector lever is in a Manual gear range First, Second, or Third.

LUBE PASSAGE

BACKING PLATE RETAINER RING (511) BACKING PLATE (510) SPRING RETAINER RING (507) LUBE PASSAGE

OVERDRIVE SUN GEAR OVERDRIVE ROLLER CLUTCH INNER CAM FIBER CLUTCH PLATE ASSEMBLY (509) STEEL CLUTCH PLATE (508)

509

510

511

21

15

APPLY COMPONENTS4TH CLUTCH ASSEMBLY (523-533)

4TH CLUTCH RELEASE:

To release the 4th clutch, 4th clutch fluid exhausts through the 4th clutch fluid circuit, allowing pressure at the 4th clutch piston (528) to decrease. In the absence of fluid pressure, spring force from the spring assembly (532) moves the 4th clutch piston away from the clutch pack. This disengages the steel plates (526) and fiber plates (525) from the backing plate (524), thereby allowing the overrun clutch housing and overdrive sun gear to rotate.

4TH CLUTCH APPLY FLUID PASSAGE

4TH CLUTCH:

FIBER STEEL CLUTCH PLATE CLUTCH ASSEMBLY PLATE (525) (526)

INNER SEAL (527)

4TH CLUTCH ORIFICE (530)

OUTER SEAL (531)

The 4th clutch assembly, located in the 4th clutch housing (529), is held stationary to the transmission case (7) by the 4th clutch housing bolt (26). The external teeth on the reaction (steel) plates (526) are splined to the 4th clutch housing while the internal teeth on the fiber clutch plate assemblies (525) are splined to the overrun clutch housing (504). The 4th clutch is applied only when the transmission is in Fourth gear to provide an overdrive gear ratio.4TH CLUTCH APPLY:


To apply the 4th clutch, 4th clutch fluid is fed from the case, through the 4th clutch housing bolt (26) and behind the 4th clutch piston (528). 4th clutch fluid pressure forces the piston against the 4th clutch spring assembly (532) to cushion the apply. As fluid pressure increases, the piston compresses the clutch plates (steel and fiber) together until they are held against the 4th clutch backing plate (524). When fully applied, the steel plates (526) and fiber plates (525) are locked together and held stationary by the 4th clutch housing. The internal teeth on the fiber plates hold the overrun clutch housing (504) stationary to prevent the overdrive sun gear from rotating. The orifice cup plug (530) is pressed into the 4th clutch housing. Air in the 4th clutch fluid circuit is forced out the orifice when 4th clutch fluid pressure increases to prevent excess cushion during 4th clutch apply.

4TH CLUTCH BACKING PLATE (524)

Plugged fourth apply passage, damaged clutch plates, return spring assembly or piston seals can cause no fourth/slips in fourth.

4TH CLUTCH HOUSING (529)

SPRING RETAINER RING (533) 4TH CLUTCH HOUSING BOLT CASE 4TH CLUTCH (26) (7) APPLY FLUID 530 532 533

BACKING PLATE 4TH CLUTCH RETAINER RING PISTON (523) (528)

523

524

525

526

528

529

16

Figure 16

APPLY COMPONENTSOVERRUN CLUTCH RELEASE:OVERRUN CLUTCH HOUSING (504)

To release the overrun clutch, overrun clutch fluid exhausts through the overrun clutch housing inner hub and into the oil pump hub, allowing pressure at the overrun clutch piston (505) to decrease. In the absence of fluid pressure, spring force from the spring assembly (506) moves the overrun clutch piston (505) away from the clutch pack. This disengages the steel plates (508) and the fiber plates (509) from the backing plate (510) and disconnects the overrun clutch housing from the overdrive carrier.OVERRUN CLUTCH BALL CHECK VALVE

During the exhaust of overrun clutch fluid, the overrun clutch ball check valve, located in the overrun clutch housing, unseats. Centrifugal force, resulting from the rotation of the overrun clutch housing, forces residual overrun clutch fluid to the outside of the piston housing and past the unseated ball check valve. If this fluid did not completely exhaust from behind the piston, there could be a partial apply, or drag, of the overrun clutch plates.

OVERRUN CLUTCH:

APPLIED

RELEASED

OVERRUN CLUTCH APPLY:

To apply the overrun clutch, overrun clutch fluid is fed through the oil pump hub to the inner hub of the overrun clutch housing. Feed holes in the inner hub allow fluid to enter the housing behind the overrun clutch piston (505). Overrun clutch fluid pressure seats the overrun clutch ball check valve (located in the housing) and moves the piston to compress the spring assembly (506) to cushion the apply. As fluid pressure increases, the piston compresses the clutch plates (steel and fiber) together until they are held against the overrun clutch backing plate (510). Also, the increase in fluid pressure forces any air in the overrun clutch fluid circuit to exhaust past the ball check valve, before it seats, to prevent excess cushion during clutch apply. When fully applied, the steel plates (508) and fiber plates (509) are locked together, thereby holding the overrun clutch housing and overdrive carrier together. This forces the housing and carrier to turn as one unit during engine compression braking in the Manual gear ranges.If inoperative the overrun clutch can cause loss of drive, no overrun braking - D3, No fourth gear - D4, engine stall and harsh shifts from D4 to D3, D2 or D1.505 506 507 508


OVERRUN CLUTCH APPLY FLUID

OVERRUN CLUTCH PISTON ASSEMBLY (505)

OVERRUN CLUTCH HOUSING (504) LUBE PASSAGE

Figure 17

509 510

The overrun clutch assembly is located in the overrun clutch housing (504). The external teeth on the reaction (steel) plates (508) are splined to the overrun clutch housing while the internal teeth on the fiber clutch plate assemblies (509) are splined to the overdrive carrier assembly (514). The overrun clutch is applied only when the shift selector lever is in a Manual gear range First, Second, or Third.

LUBE PASSAGE

BACKING PLATE RETAINER RING (511) BACKING PLATE (510) SPRING RETAINER RING (507) LUBE PASSAGE

OVERDRIVE SUN GEAR OVERDRIVE ROLLER CLUTCH INNER CAM FIBER CLUTCH PLATE ASSEMBLY (509) STEEL CLUTCH PLATE (508)

511

17

APPLY COMPONENTSOVERDRIVE ROLLER CLUTCH:

The overdrive roller clutch assembly (512) is located between the overdrive carrier assembly (514) and overrun clutch housing (504). The overdrive carrier functions as the outer race for the roller clutch while the overrun clutch housing functions as the inner cam. The overdrive roller clutch is a type of one-way clutch that prevents the overrun clutch housing from rotating clockwise faster than the overdrive carrier assembly. The overdrive roller clutch is holding, and effective, when the vehicle is accelerating and the transmission is in First, Second, Third, or Reverse gear.4TH CLUTCH ASSEMBLY OVERDRIVE OVERDRIVE ROLLER INTERNAL CLUTCH GEAR (512) INNER CAM

OVERDRIVE CARRIER ASSEMBLY (514) (OUTER RACE)

OVERDRIVE ROLLER CLUTCH (512)

OUTER RACE SUN GEAR OVERRUN CLUTCH HOUSING (504) OVERDRIVE CARRIER ASSEMBLY (514) FORWARD CLUTCH HOUSING (602)

A damaged overdrive roller clutch can cause loss of drive.OVERDRIVE ROLLER CLUTCH HOLDING: (EXAMPLE A)

OVERDRIVE CARRIER ASSEMBLY (514) OVERDRIVE ROLLER CLUTCH HOLDING

EXAMPLE "A" DIRECT DRIVE FORWARD CLUTCH HOUSING (INTERNAL GEAR)

G AT I N OT RD

H

EL

In First, Second, Third and Reverse gears the 4th clutch is released and the overrun clutch housing is free to rotate. The overdrive carrier pinion gears are in mesh with both the overdrive internal gear [part of the forward clutch housing (602)] and the overdrive sun gear [part of the overrun clutch housing (504)]. Power flow drives the overdrive carrier clockwise. Vehicle load on the forward clutch housing causes the pinion gears to attempt to rotate counterclockwise on their pins around the internal gear as they travel with the carrier assembly. Therefore, the pinion gears attempt to drive the sun gear clockwise, faster than the overdrive carrier. However, this causes the rollers to move up the ramps and wedge between the inner cam and outer race, thereby locking the overrun clutch housing and overdrive carrier together. With the sun gear and overdrive carrier rotating at the same speed, the pinion gears do not rotate on their pins but do travel clockwise with the carrier and drive the forward clutch housing. Therefore, a direct drive 1:1 gear ratio is obtained through the overdrive planetary gear set in First, Second, Third and Reverse gears with the overdrive roller clutch holding.OVERDRIVE ROLLER CLUTCH RELEASED: (EXAMPLE B)

(OUTER RACE)

OVERRUN CLUTCH HOUSING AND SUN GEAR (INNER CAM) EXAMPLE "B" OVERDRIVE FORWARD CLUTCH HOUSING (INTERNAL GEAR)

OVERDRIVE CARRIER ASSEMBLY (514) OVERDRIVE ROLLER CLUTCH OVERRUNNING

G AT I N OT RD

H

EL

(OUTER RACE)

OVERRUN CLUTCH HOUSING AND SUN GEAR (INNER CAM)

The roller clutch releases when the overdrive carrier rotates clockwise faster than the overrun clutch housing. This causes the rollers to move down the ramp and rotate freely between the inner cam and outer race. This action occurs in Fourth gear when the 4th clutch is applied. The 4th clutch fiber plates (525) are splined to the overrun clutch housing and hold the housing and overdrive sun gear stationary to the transmission case. As power flow drives the overdrive carrier clockwise, the carrier overruns the roller clutch. The overdrive carrier pinion gears rotate clockwise on their pins and walk around the stationary sun gear. The pinions then drive the forward clutch housing (through the internal gear) in an overdrive gear ratio of approximately .75:1. The overdrive carrier also overruns the overdrive roller clutch during coast conditions (throttle released) in Overdrive Range - First, Second, and Third gears and in Reverse and when vehicle speed is greater than engine speed. This causes the forward clutch housing to be driven by vehicle speed faster than the overdrive carrier is being driven by engine speed. This drives the pinion gears clockwise and the sun gear counterclockwise, thereby overrunning the overdrive roller clutch. However, in the Manual gear ranges, the overrun clutch is applied to connect the overrun clutch housing and overdrive carrier. This prevents the overdrive carrier from overrunning the overdrive roller clutch during coast conditions.

18

Figure 18

APPLY COMPONENTSclutch pack is a waved steel plate (609) that, in addition to the spring assembly and forward clutch orifice, helps control the apply rate of the forward clutch. When fully applied, the steel plates (610) and fiber clutch plate assemblies (611) are locked together, thereby holding the forward clutch housing and the forward clutch hub (613) together. This forces the forward clutch hub to rotate at the same speed as the forward clutch housing.FORWARD CLUTCH HOUSING ASSEMBLY (602)

FORWARD CLUTCH RELEASE:

If inoperative the forward clutch can cause forward motion in Neutral, loss of drive, engine stall, third gear starts and harsh shifts from D to R.FORWARD CLUTCH:

To release the forward clutch, drive fluid exhausts from the piston, through the inner hub of the forward clutch housing and into the turbine shaft. In the absence of fluid pressure, spring force from the spring assembly (607) moves the forward clutch piston away from the clutch plates. ThisFORWARD CLUTCH BALL CHECK VALVE

APPLIED

RELEASED

FORWARD CLUTCH APPLY:

To apply the forward clutch, drive fluid is fed through the turbine shaft to the inner hub of the forward clutch housing. Feed holes in the inner hub allow fluid to enter the housing behind the inner area of the forward clutch piston (606) [between the inner piston seal and the intermediate seal assembly (685)]. Drive fluid pressure on the inner area moves the piston and compresses the spring assembly (607) to cushion the apply. As fluid pressure increases on the inner area, the piston compresses the clutch plates (steel and fiber) until they are held against the direct clutch hub (615). At the same time, drive fluid is fed through the forward clutch orifice in the intermediate seal assembly to feed fluid to the outer area of the piston [between the intermediate seal assembly (685) and the outer piston seal]. This fluid pressure seats the forward clutch ball check valve and increases the holding force on the clutch pack. Also, the increase in fluid pressure forces any air in the drive fluid circuit to exhaust past the ball check valve, before it seats, to prevent excess cushion during clutch apply. Also included in the685 606 607 608 609

FORWARD CLUTCH HOUSING ASSEMBLY (602) FORWARD CLUTCH ORIFICE DRIVE APPLY FLUID

OVERDRIVE INTERNAL GEAR SPRING RETAINER RING (608) LUBE PASSAGE 613 614 RETAINER RING (616)

FORWARD CLUTCH PISTON INTERMEDIATE SEAL ASSEMBLY (685) FORWARD CLUTCH PISTON (606) 611

610

Figure 19

The forward clutch assembly is located in the forward clutch housing (602). The external teeth on the reaction (steel) plates (610) are splined to the forward clutch housing while the internal teeth on the fiber clutch plate assemblies (611) are splined to the forward clutch hub (613). The forward clutch is applied in all forward gear ranges to transfer engine torque from the overdrive planetary gear set to the output and reaction planetary gear sets.

disengages the steel plates (610), fiber clutch plate assemblies (611) and waved plate (609) from the direct clutch hub (615) and disconnects the forward clutch housing from the forward clutch hub (613). The forward clutch orifice controls the exhaust of drive fluid from the outer area of the piston. This action, in addition to the spring assembly, helps control the release of the forward clutch plates. During the exhaust of drive fluid, the forward clutch ball check valve, located in the forward clutch housing (602), unseats. Centrifugal force, resulting from the rotation of the forward clutch housing, forces residual drive fluid to the outside of the housing and past the unseated ball check valve. If this fluid did not completely exhaust from behind the piston, there could be a partial apply, or drag, of the forward clutch plates.

FIBER STEEL LUBE WAVED CLUTCH CLUTCH PASSAGE CLUTCH PLATE PLATE PLATE ASSEMBLY (610) (609) (611) DIRECT CLUTCH HUB (615)


LUBE PASSAGE

FORWARD CLUTCH HUB (613)

THRUST WASHER (612)

612

615

616

19

APPLY COMPONENTSIn Reverse, 3rd/reverse fluid is fed to the inner area of the piston through the 3rd/ reverse circuit as in Third and Fourth gears. However, in Reverse, reverse fluid is fed through the reverse fluid circuit to the outer area of the direct clutch piston [between the intermediate seal (622) and the outer piston seal]. Reverse fluid pressure seats the direct clutch ball check valve and acts on the outer area of the piston. This fluid pressure increases the holding capacity of the direct clutch plates in Reverse, as compared to Third gear. Also, the increase in reverse fluid pressure forces any air in the reverse fluid circuit to exhaust past the ball check valve, before it seats, to prevent excess cushion during clutch apply.DIRECT CLUTCH RELEASE:

DIRECT CLUTCH HOUSING ASSEMBLY (623)

DIRECT CLUTCH:

The direct clutch assembly is located in the direct clutch housing (623). The external teeth on the reaction (steel) plates (618) are splined to the direct clutch housing while the internal teeth on the fiber clutch plate assemblies (611) are splined to the direct clutch hub (615), which is connected to the forward clutch housing (602). The direct clutch is applied when the transmission is in Third or Fourth gears and in Reverse.DIRECT CLUTCH APPLY:

To release the direct clutch, apply fluid (3rd/reverse and/or reverse) exhausts from the piston, through the inner hub of the

direct clutch housing and into the center support assembly (640). In the absence of fluid pressure, spring force from the spring assembly (607) moves the direct clutch piston away from the clutch plates. This disengages the steel plates (618), fiber clutch plate assemblies (611) and waved plate (609) from the direct clutch backing plate (617) and disconnects the direct clutch housing from the direct clutch hub (615). During the exhaust of reverse fluid, the direct clutch ball check valve, located in the direct clutch housing, unseats. Centrifugal force, resulting from the rotation of the direct clutch housing, forces residual reverse fluid to the outside of the housing and past the unseated ball check valve. If this fluid did not completely exhaust from behind the piston, there could be a partial apply, or drag, of the direct clutch plates.

DIRECT CLUTCH HOUSING ASSEMBLY (623) BACKING PLATE (617)

APPLIED LUBE PASSAGE

SPRING ASSEMBLY (607) LUBE PASSAGE SPRING RETAINER RING (608) DIRECT CLUTCH PISTON INTERMEDIATE SEAL (622) BACKING PLATE RETAINING RING (616) 618 609 608

REVERSE APPLY FLUID

3RD/REVERSE APPLY FLUID LUBE PASSAGE

If inoperative the direct clutch can cause no reverse; no second gear in D4, D3, D2 or D1; no third gear in D4 or D3; third gear starts; soft shifts to reverse, reverse to drive, second to third gear and third to second gear.616 617 611

INTERMEDIATE SPRAG CLUTCH INNER CAM DIRECT CLUTCH PISTON ASSEMBLY (619) 607 619 622

20

Figure 20

To apply the direct clutch for Third and Fourth gears, 3rd/reverse fluid is fed from the transmission case (7), through the center support (640) and into the inner hub of the direct clutch housing. Feed holes in the inner hub allow 3rd/reverse fluid to enter the housing behind the inner area of the direct clutch piston (619) [between the inner piston seal and the intermediate seal (622)]. 3rd/reverse fluid pressure moves the piston to compress the spring assembly (607). As fluid pressure increases, the piston compresses the clutch plates (steel and fiber) until they are held against the direct clutch backing plate (617). Also included in the assembly is a waved steel plate (609) that, in addition to the spring assembly, helps cushion the apply of the direct clutch. When fully applied, the steel plates (618), fiber clutch plate assemblies (611) and waved plate (609) are locked together, thereby holding the direct clutch housing and direct clutch hub (615) together. This forces the direct clutch housing to rotate at the same speed as the forward clutch housing.

STEEL FIBER CLUTCH CLUTCH PLATE PLATE (618) ASSEMBLY (611)

WAVED CLUTCH PLATE (609)

LUBE PASSAGE

DIRECT CLUTCH BALL CHECK VALVE EX

RELEASED

APPLY COMPONENTSMANUAL 2-1 BAND SERVO RELEASE:

DIRECT CLUTCH HOUSING ASSEMBLY (623)


The manual 2-1 band servo assembly is held in the release position by PRND43 fluid pressure acting on the manual 2-1 band servo piston (58) when the gear selector is in the Park, Reverse, Neutral, Overdrive and Manual Third positions. PRND43 fluid is fed between the transmission case and manual 2-1 band servo piston to assist spring force in keeping the piston and apply pin in the released position. Even with FBA fluid pressure present, PRND43 fluid pressure and spring force will keep the piston, apply pin and manual 2-1 band in the released position, as in Overdrive Range - Second Gear. When the gear selector is in either Manual Second Or Manual First (PRND43 fluid exhausted), and the transmission downshifts from Second gear to First gear, FBA fluid exhausts from the servo piston. This allows spring force to move the piston and apply pin away from the manual 2-1 band, thereby releasing the manual 2-1 band assembly from the direct clutch housing.An inoperative manual 2-1 servo assembly/manual 2-1 band assembly can cause no engine braking in manual second (second gear), no first gear in manual third or manual second, no third gear in manual third or no manual third to manual second shift.

MANUAL 2-1 BAND SERVO ASSEMBLY AND MANUAL 2-1 BAND ASSEMBLY:

The manual 2-1 band servo assembly (55-60), located in the bottom of the transmission case (7), applies the manual 2-1 band assembly (628) when the gear selector is in either the Manual Second or Manual First positions and the transmission is in Second gear. The manual 2-1 band assembly is held stationary to the transmission case by the band anchor pin (80) and wraps around the direct clutch housing assembly (623) . When compressed by the manual 2-1 band servo assembly, the band holds the direct clutch housing (623), sun gear shaft (649) and sun gear (650) stationary to the case. This prevents the intermediate sprag clutch (624) from overrunning during coast conditions in Manual Second - Second Gear or Manual First - Second Gear to provide engine compression braking.MANUAL 2-1 BAND SERVO APPLY:

MANUAL 2-1 BAND ANCHOR PIN (80)


To apply the manual 2-1 band servo, Front Band Apply (FBA) fluid is fed between the spacer plate (46) and manual 2-1 band servo piston (58). FBA fluid pressure forces the piston to compress the piston spring (60) and move the piston apply pin (55) toward the band. The apply pin compresses the band assembly around the direct clutch housing and holds the housing stationary to the case. During apply, piston spring force helps control the apply feel of the manual 2-1 band assembly.60 MANUAL 2-1 BAND SERVO PISTON PIN (55) CASE (7) PISTON PIN RETAINER RING (56) 57 PISTON SEAL (57) 56 55 PRND43 RELEASE FLUID CONTROL VALVE BODY (44) PISTON CUSHION SPRING (60) MANUAL 2-1 BAND SERVO PISTON (58) FRONT BAND APPLY FLUID (FBA) SPACER PLATE (46)

58

Figure 21

21

APPLY COMPONENTSINTERMEDIATE CLUTCH PLATES (630-632,684)

INTERMEDIATE SPRAG CLUTCH:

The intermediate sprag clutch assembly (624-627) is located between the intermediate clutch plate assemblies (631) and the direct clutch housing assembly (623). The intermediate clutch plate assemblies are splined to the intermediate sprag clutch outer race (625) while the intermediate sprag inner cam is pressed onto the direct clutch housing. The intermediate sprag clutch is a type of one-way clutch that, when effective, prevents the direct clutch housing from rotating counterclockwise. The sprag clutch is holding, and effective, when the vehicle is accelerating and the transmission is in Overdrive Range - Second Gear.INTERMEDIATE SPRAG CLUTCH HOLDING: (EXAMPLE A)

DIRECT CLUTCH HOUSING ASSEMBLY (623) OUTER RACE (625)

INTERMEDIATE SPRAG CLUTCH ASSEMBLY (624-627) EXAMPLE "A" INTERMEDIATE SPRAG CLUTCH HOLDING

HELD

HELDLONG DIAGONAL DIRECT CLUTCH HOUSING (623) (INNER CAM) EXAMPLE "B" INTERMEDIATE SPRAG CLUTCH OVERRUNNING

In Second gear, power flow attempts to drive the direct clutch housing counterclockwise which pivots the sprags toward their long diagonals. The long diagonal of the sprag is greater than the distance between the inner cam and outer race, causing the sprags to lock against the intermediate clutch sprag outer race (625). However, in Second gear the intermediate clutch is applied and the outer race is held stationary to the transmission case (7). Therefore, the sprag assembly, being locked between the outer race and direct clutch housing (inner cam), holds the direct clutch housing (623), sun gear shaft (649) and sun gear (650) stationary to obtain a Second gear ratio through the transmission gear sets. The direct clutch housing is also driven counterclockwise in First gear and the sprags lock the direct clutch housing and outer race together, as in Second gear. However, the intermediate clutch is released in First gear which allows the outer race (625) to rotate with the direct clutch housing and not affect power flow. This is shown in the range reference chart (page 11) as Holding But Not Effective.INTERMEDIATE SPRAG CLUTCH RELEASED: (EXAMPLE B)

OUTER RACE (625)

HELD

The intermediate sprag clutch releases w

4l80e hydraulic book

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