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TCRA 2005RWD. Chrysler TCC Issues

II Part Presentation byBob Warnke and Ed Lee

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Part 1: Control and InfluencePart 2: Converter Assembly

*Application: ’93 latter RWD Chrysler11” Converter with 4 spooled switch valve.

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Common calls to Tech Support:

• Excess TCC slip or 740 code• TCC RPM surge or cycle • Engine stall on engagement Fwd. or Revs.• Noise, hydraulic moan or buzz

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Experience has shown… • Cooler flow can be too high!

0ver 4.0 GPM may cause an over-heat as rapid flow reduces heat dissipation.

• Cooler flow can be insufficient!Minimum of 2.7 GPM applied, 46RE Minimum of 3.2 GPM applied, 47RE

• Restricted radiators can cause slip/shudder.

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Cooler Restrictions

Auxiliary Cooler Drain-back

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Excess cooler/head pressure can create TCC slip.

Head pressure can be reduced with bypass valves

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Cooler Flow Chart

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Experience has proven…• Increasing line pressure often increases:

Release Pressure - Noise - TCC slippage.• As radiator restrictions increase, reaction of

TCC apply and exhaust of release slow down.

• Converter restrictions or leakage create; TCC slip, stall on engagement, low cooler flow and converter overheat.

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Release oil pressure location

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Line vs. Apply - Release pressure• Line & 4th oil pressure must rise at TCC apply.• Release pressure must drop to -0-, rapidly at apply

TCC Apply Pressure

50556065707580859095

100105110115120

Line

or T

CC

App

ly (P

SI)

Drive Idle D-3 TCC off mid-throttle

D-3 TCC Apply mid-

throttle

O.D. or D-3 TCC

Apply W.O.T.

O.D. TCC Apply

worn T.V. valves

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Valve body control of converter feed and apply

4 spool switch valve pressure regulatorTCC apply /release feed and flow

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Engine Stall on EngagementCommon Cause: (Gas or Diesel)

• Cooler restriction• Converter restriction• Pump wear or volume issue• Flex plate stand-off

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Poor Converter Charge, caused by low pump inlet pressure

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Turbine shaft and flex plate position

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Noise Issues:

• Restricted cooler• Pump inlet or output pressure low • Valve body wear• Restricted converter

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Sump pressure vs. Converter flow

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Welcome to Part Two

Ed LeeSonnax Technical Specialist

Converter Flow and Assembly Issues

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THINK FLOW740 Codes

A Converter is a Converter is a Converter…

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THE PROBLEM:

• One of the most common tech calls is on the 740 codes on the rear wheel drive Chryslers

• 740 codes are torque converter slip codes

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The Common Fix:

• Usually the technician addresses the fluid, the hydraulic integrity, proper cooler flow, and the proper friction material

• When all of these solutions have been exhausted and the problem still exists…you need to take a closer look…

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A CLOSER LOOK…

• Had a vehicle with 740 code• Bob sent me the converter• We found that the clutch surfaces were not

machined properly, and a few other minor things…BUT not enough to cause the code

• So, finally we took a CLOSER LOOK at the FLOW within the converter

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THE TEST…

• Did three (3) different tests on seven (7) different torque converters– All converters were identical on the outside– All converters were 90 degree 518 transmission torque

converters (DACCO 785)– All converters had OE turbine hub bushings– All converters had new high carbon clutch linings– All converters had red damper springs– All converters had .025 clutch release clearance

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THE TEST…

• The DIFFERENCE in the seven (7) torque converters was …the turbine hub and thrust washer/bearing to cover combinations.

• Let’s take a look at the 7 converters…

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Number 1 OE Hub and fiber thrust washer

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Number 2 OE Turbine HubOE Bearing (Sonnax CH-N-8)

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Number 3 Aftermarket Turbine Hub and Fiber Thrust Washer

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Number 4 Aftermarket Turbine Hub and OE Bearing

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Number 5 Different Aftermarket Turbine Hub and Brass Thrust Washer

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Number 6 Same as #1 except the turbine hub bushing is installed too deep

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Number 7 OE Turbine Hub and a Phenolic Thrust Washer (Test 1)

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Number 7 OE Turbine Hub and a Phenolic Thrust Washer (Test 2)

THRUST WASHER IS TURNED OVER

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The Process… first trial

• Sent the first six converters to Certified Transmissions in Omaha, Nebraska

• Certified did a data acquisition dyno test• Test results were similar to some of the Pin

Point test data found during the second trial

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The Process…second trial• These six converters were then sent to Bob

Warnke in Wisconsin to test and monitor isolated circuits:– He tapped the release pressure between the pressure

regulator valve and the converter– He tapped the apply pressure between the TCC switch

valve and the converter– Cooler flow was checked through all ranges with the

Sonnaflow, TCC on-off– Cooler restriction was varied from free flow to 50% of

release pressure– Sump pressure was monitored

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The Process…another converter

• Bob added a seventh converter from a local transmission shop…he received this because of repeat engine stalls on engagements…and since it had flow problems, Bob decided to add it to the process

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Bob’s Observations…for all 7• The most critical issues are:

– Flow when not in lockup and release pressure– Release pressure over 100 lbs has negative affect on

OE hydraulics. Increasing line pressure and higher pressure in reverse reacts on switch and regulator valves

– Low release oil flow increases converter heat, raises stall RPM and contributes to delayed engagements

– Excess cooler restriction increases converter and hydraulic noise

– Lower converter oil flow increases the pump pressurization upon shutdown

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Bob’s Results…on all 7

• Converters– #5 and #1 were tied for highest overall averaged flow– #6 had the lowest, with #2 close to it with the lowest overall flow– #2 had the highest release pressure overall– #5 had the lowest release pressure overall– #3 had almost no sump pressure or re-pressurization– #6 had the highest sump and re-pressurizationAs radiator head pressure increases (more restriction in the cooler)

cooler flow decreases and release pressure increases proportionately.

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The Process…third trial

• Ed Lee flow tested the individual converters.

• A modified compressor with ATF and a large air reserve is used to provide controlled pressure and flow over a measured time period

• Fluid flow is collected and measured

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The Results…• Converter (hub / thrust) GPM @ 40 PSI• Number 1 OE / Fiber 6.843• Number 2 OE / OE Bearing 3.656• Number 3 Aftermarket / Fiber 6.280• Number 4 Aftermarket / OE Bearing 3.000• Number 5 2nd Aftermarket

/ Brass Washer 8.438• Number 6 #1 with hub bushing

installed too deep 1.875• Number 7 OE / Phenolic Washer 7.969• Number 7* With washer upside down 3.469

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THE END RESULT…

• ANYTHING LESS THAN 3 gallons per minute through the individual components, puts you in jeopardy of a 740 code

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TCRA 2005RWD. Chrysler TCC Issues

II Part Presentation byBob Warnke and Ed Lee

Thank You