Level 3 ApprenticeshipLevel 3 Apprenticeship
InertiaInertia
• DefinitionDefinition: An object at rest tends to remain at rest, and an object in motion tends to continue in motion in a straight line unless acted upon by an outside force..
Inertia ContinuedInertia Continued
• For example, passengers in an accelerating automobile feel the force of the seat against their backs overcoming their inertia so as to increase their velocity. As the car decelerates, the passengers tend to continue in motion and lurch forward. If the car turns a corner, then a package on the car seat will slide across the seat as the inertia of the package causes it to continue moving in a straight line
External force is holding
Internal forces keepmoving
Forces within the vehicle resist movement
External forces continue to move
Rear CollisionRear Collision
Simple CollisionSimple Collision
Structure CollapsesUniformly
Simple CollisionSimple Collision
Pull
Hold
Strength and design of Body structure will dictate the deflection of collision forces acting upon it
DeflectionDeflection
• a change of course after hitting somebody or something, or a changing of an objects course by being hit by it
Deflection of ForcesDeflection of Forces
Frame DesignFrame Design
Deflection From Direction of Deflection From Direction of TravelTravel
Offset frontalOffset frontal
Deflection From Direction of Deflection From Direction of TravelTravel
Side impactSide impact
Another ExampleAnother Example
Three Section PrincipleThree Section Principle
Front Centre RearFront Centre Rear
Frontal Collision ForcesFrontal Collision Forces
Frontal ImpactFrontal Impact
1
Stage 1Stage 1
Stage 2Stage 2
Stage 3Stage 3
4
Stage 4Stage 4
Forces in a Rear CollisionForces in a Rear Collision
Stage 1Stage 1
Stage 2Stage 2
Stage 3Stage 3
Stage 4Stage 4
Side ImpactSide Impact
Side ImpactSide Impact
Side ImpactSide Impact
#2#2
#3#3
Forces Present in a RolloverForces Present in a Rollover
Typical RolloverTypical Rollover
#2#2
#3#3
MeasurementMeasurementReferenceReferenceSourcesSources
MeasurementMeasurementReferenceReferenceSourcesSources
CENTRE LINECENTRE LINE
• IS AN IMAGINARY LINE THAT RUNS LENGTHWISE THROUGH THE VEHICLE AND IS A REFERENCE FOR DETERMINING LATERALALIGNMENT AND MEASUREMENT
LATERAL LATERAL MEASURMENTMEASURMENT
Centre Plane
Centre Line
CL
CENTERLINECENTERLINE IS USED TO REFERENCE WIDTH THROUGHOUT THE VEHICLE. COMPONENTS MAY BE POSITIONED EQUALLYEQUALLY OFF OF CENTRE (SYMMETRICAL)OR UNEQUALLYUNEQUALLY OFF OF CENTRE (ASYMETRICAL)
DATUM • IS AN IMAGINARY LINE WHICH IS USED TO ESTABLISH
THE HEIGHT OF THE VEHICLES COMPONENTS AND IS A REFERENCE FOR DETERMINING
VERTICAL MISALIGNMENT
DATUM PLANE
DATUM PLANEDATUM PLANE
•The reference line for all vertical body dimensions
ZERO PLANESZERO PLANES
CENTREFRONT REAR
From the ‘Zero’ Plane we can establish length measurement
0
0
From the ‘Centre’ Plane we can establish width
The ‘Datum’ Plane establishes Height dimensions
With these dimensions we can reference all known control points
L
W
H
Measuring ToolsMeasuring Tools
Datum Length Vs. Point to Point
TYPES OF MEASURING SYSTEMSTYPES OF MEASURING SYSTEMS
1. UNIVERSAL1. UNIVERSAL -Mechanical -Laser -Sonic
2. DEDICATED BENCH AND FIXTURE MEASURING2. DEDICATED BENCH AND FIXTURE MEASURING -Mechanical-Mechanical -Laser-Laser
SELF CENTERING GAUGE
Strut Tower GaugeStrut Tower Gauge
Cross member Pin
Digital Tram GaugeDigital Tram Gauge
Most Mitchell, Chief, & Hein-Werner specificationscan be measured using a tram gauge set at equallengths. Measurements can be read directly fromthe tram gauge bar scale or by measuring the distance from pointer to pointer
Tram GaugeTram Gauge
Tape MeasureTape Measure
TermsTerms
• perpendicular
1. at right angles: at right angles to a line or plane2. vertical: perfectly vertical
Laser SystemsLaser Systems
- Single target- Mirrored / Beam splitter / 3d- Multi laser 3d- Reflective pulse laser
Basic theory behind Genesis style systems
Multi TargetLaser
Universal System
Fixed Universal systemFixed Universal system
Universal Bench
Dedicated Bench
Laser Measuring
DatalinerDatalinerLaser measuringLaser measuringsystemsystem
Dedicated Bench and Fixture System
Measuring Systems on the Measuring Systems on the InternetInternet
• http://www.car-o-liner.se/us/• http://www.dataliner.se/• http://www.hein-werner.com/• http://www.chiefautomotive.com/• http://www.lasermateusa.com/• http://www.celette.com/
CRITICAL MEASUREMENTCRITICAL MEASUREMENT
REFERS TO ANY DISTANCE FROM ONE POINT TO ANOTHER THAT MUST BE MEASURED ACCURATELY
TO DIAGNOSE STRUCTURAL DAMAGE
THESE AREAS INCLUDE: • TORQUE BOX WIDTH AND LENGTH• FRAME HORN WIDTH AND LENGTH
• BALL JOINT POSITION• SRUT TOWER POSITION
• SUSPENSION MOUNTING POINTS ETC.
WHILE MOST MEASUREMENTS REQUIRE A DIMENSIONSHEET, QUITE OFTEN CHECKING ONE SIDE TO
ANOTHER WILL SUFFICE IF NO DIMENSION EXSISTS
BASIC STRUCTURAL ALIGNMENT
Body Centre MarkingsBody Centre Markings
Picture the Vehicle as a Box
The Box is Divided Into 3 Sections
BY HANGING GAUGES ON THE UNEVEN BODY OF THEVEHICLE ALLOWS US TO LOOK AT THE UNDERBODY
AS A FLAT LEVEL PLANE. THE GAUGES ALSO DIVIDE THE PLANE INTO THREE SECTIONS
Front Centre RearFront Centre Rear
THIS ALLOWS US TO VIEW THE GAUGES TO DETERMINE
IF THE PLANE HAS BEEN DISTORTED BY THE COLLISION
EXAMPLES OF LATERAL AND VERTICAL MISALIGNMENT
INCORRECT DATUM
While level and datum both relate to vertical While level and datum both relate to vertical (up/down) alignment all three sections are still(up/down) alignment all three sections are still
Level or parallel with each otherLevel or parallel with each other
TWISTTWIST
This structure is out of parallel (twist)This structure is out of parallel (twist)this type of damage is not considered athis type of damage is not considered adatum misalignment as the front and datum misalignment as the front and
rear sections are not up or down relativerear sections are not up or down relativeto the centre sectionto the centre section
Incorrect datumIncorrect datum
On the other hand, a vehicles front or rear On the other hand, a vehicles front or rear section can be vertically misaligned (datum)section can be vertically misaligned (datum)and still remain parallel (level) to the centreand still remain parallel (level) to the centre
sectionsection
Datum and Level MisalignmentDatum and Level Misalignment
THREE STEPS FOR GAUGING:
1. DIVIDE THE VEHICLE INTO THREE SECTIONS2. LOCATE ITS CONTROL POINTS3. ESTABLISH A BASE FOR THE GAUGING PROCESS
CONTROL POINTS:CONTROL POINTS:
• A POINT ON WHICH ANY STRUCTURAL ALIGNMENT IS DEPENDENT• POINTS UPON WHICH ALL MEASURING MUST BE TAKEN TO DETECT COLLISION DAMAGE
BASIC CONTROL POINTS
MANUFACTURERS USECONTROL POINTS FORPOSITIONING OF STRUCTUREDURING MANUFACTURE
TECHNICIANS USE THEM AS GUIDES DURING THE REPAIR PROCESS
COMMON REFERENCE AREAS:- HOLES- BOLTS- STUDS- SUSPENSION MOUNTING POINTS- RIVETS
ESTABLISHING A BASE
FIRST ESTABLISH THE CENTRE SECTION
22
33
BY INSTALL GAUGES AT THE EXTREME FRONT ANDREAR OF THE STRUCTURE, WE DIVIDE THE VEHICLE INTO
THREE BASIC SECTIONS FOR GAUGING PURPOSES
• WITH THESE GAUGES INSTALLED, YOU CAN NOW COMPARE THE TWO BASE GAUGES TO EACH OTHER TO CHECK THE
CONDITION OF THE CENTRE SECTION.• YOU CAN THEN SIGHT THE FRONT AND REAR SECTIONS
FROM THE BASE SECTION TO DETERMINE COMPLETEAND OVERALL STRUCTURAL CONDITION
ADDITIONAL CONTROL POINTS
- LOWER SUSPENSION IF IN THE AREA OF IMPACT
- STRUT TOWERS IF UNITIZED
- STEERING ATTACHMENT POINTS
CONTROL AREAS
- MAY REQUIRE REMOVAL OF MECHANICAL COMPONENTS TO FACILITATE MOUNTING
- MAY REQUIRE ADAPTERS TO FACILITATE MOUNTING
USING DATUM
- WHAT IS THE PURPOSE OF DATUM IN TERMS OF COLLISION DAMAGE ANALYSIS AND REPAIR?
- WHEN SHOULD DATUM BE USED?
PURPOSE
- PROPER SHEETMETAL ALIGNMENT- PROPER HEIGHT OF SUSPENSION MOUNTING AREAS
USAGE
- ANYTIME THE BODY STRUCTURE HAS BEEN COMPROMISED AND STRUCTURAL COMPONENTS ARE INVOLVED
...DIFFERENCES. SHEET METAL VS DIMENSION
Setting DatumSetting Datum
• Datum – 1. point of reference: a point, line, or surface
used as a basis for measurement or calculation in mapping, surveying or measuring
– Datum is used for all vertical alignment measurements
– Used to restore and check correct positioning of both sheet metal and major control points
Areas of givenMeasurement reference
Measurement ReferencePoints to Observe
Setting DatumSetting DatumControl Points
Datum Length Vs. Point to Point
WHEN READING GAUGES, USE THE CENTRESECTION AS YOUR BASE REFERENCE POINT
TAKE NOTE OF LOADED ANDTAKE NOTE OF LOADED AND UNLOADED SPECIFICATIONS!UNLOADED SPECIFICATIONS!
OPTIONAL MOUNTING PRACTICESOPTIONAL MOUNTING PRACTICES
The location of thecorrect datum willbe shown in thedimension manual
OVERCOMING OBSTACLES BY REVISING DATUM
Datum Revision SheetDatum Revision Sheet
SWAY: LATERAL MISALIGNMENT OF THE VEHICLE CENTRELINE (FRONT OR REAR)
DAMAGE RELATING TO CENTRELINE
DAMAGE RELATING TO LEVEL
• THE TERM “LEVEL” REFERS TO ALL AREAS OF THE VEHICLE BEING PARALLEL TO ONE ANOTHER
• HAS NOTHING TO DO WITH THE WAY THE VEHICLE SITS
• CAN REFER TO THE FRONT, CENTRE OR REAR SECTIONS BEING OUT OF ALIGNMENT
• SLANG TERMINOLOGY FOR THIS CONDITION WOULD BE “DOWN AT THE COWL” WHEN IN FACT THE VEHICLES LEFT FRONT RAIL IS ACTUALLY “UP”.
• AS THE VEHICLE RESTS ON ITS SUSPENSION, IT WILLAPPEAR TO SAG AT THE LEFT COWL AREA
VERTICAL MISALIGNMENT
HIGH OR LOWRAIL IS THECORRECT TERM
• THIS TERMINOLOGY LEADS YOU TO BELIEVE THAT THE VEHICLE NEEDS JACKING AT THE LEFT FRONT TORQUE BOX
• WHAT IS REQUIRED IS BLOCKING AT THIS AREA, AND A DOWN PULL ON THE LEFT FRONT RAIL
TWISTTWIST
THE EXCEPTION TO THE RULE IS “ TWIST ”.
- TWIST REFERS TO AN OUT OF LEVEL CONDITION INTHE CENTRE SECTION
- TWIST WILL HAVE (2) HIGH AND (2) LOW AREAS PRESENT
- THE HIGH AND LOW AREAS WILL BE DIAGONAL OF EACH OTHER
LEVEL ONLY REFERS TO PARALLEL WITHIN THE VEHICLESSTRUCTURE, AND HAS NOTHING AT ALL TO DO WITH HOW THE VEHICLE SITS IN RELATION TO THE FRAME
MACHINE OR THE FLOOR
LevelLevel
PERSPECTIVE VIEW AND TOP VIEW
TWIST
DAMAGE RELATING TO DATUM
INCORRECT DATUMONLY
DIFFERENCES
DIAMOND
DIAMOND
- THIS CONDITION ARISES WHEN ONE FRAME RAIL ISMISLOCATED FORWARD OR REARWARD OF THE OTHER
- THIS CONDITION IS APPARENT WHEN MEASURING THECENTER SECTION DIAGONALLY (“ X ”)
- NOT GENERALLY DIAGNOSED BY SELF CENTERINGGAUGES
COLLAPSED RAIL
- RAIL LENGTH IS COMPROMISED
- DETECTED BY LENGTH MEASUREMENT USING A TRAMBAR
CHECK LENGTH, WIDTH AND CROSS MEASURMENTS
COLLAPSED CROSSMEMBER
WIDTH MEASURMENTWIDTH MEASURMENT
STRUT TOWER AND LOWER BALL JOINT WIDTH
AFFECTS CAMBER AND SAI
BALL JOINT LENGTH
AFFECTS CASTER
STRUT TOWER AND LOWER BALL JOINT LENGTH
AFFECTS CASTER
READING SELF CENTERING GAUGES
THESE GAUGES SHOW CORRECT FRAME OR BODYALIGNMENT
Out of LevelOut of Level
SagSag
SideswaySidesway
Sequencing for DiagnosisSequencing for Diagnosis
• Twist (centre section only)• Diamond (affects centreline front and rear)
• Level (parallel readings front and rear)
• Mash (length)
• Sidesway (centreline)
• Measurements (taken constantly)
Perfect AlignmentPerfect Alignment
Sway
Out of Level Out of Level
Diamond? Diamond?
POSITION YOURSELF CORRECTLY TO VIEWTHE GAUGES
Incorrect
Correct
CORRECT DISTANCE6’-10’ AWAY
POSITIONING
TOO CLOSE
CORRECT
- THE TECHNICIAN MUST ALWAYS POSITION HIM ORHERSELF IN A CENTRAL LOCATION AS WELL AS BEING
THE CORRECT DISTANCE AWAY
WHEN GAUGING FOR PARALLEL (LEVEL), YOU MUSTSIGHT THE GAUGES WITH BOTH EYES OPEN
WHEN GAUGING FOR CENTRELINE (LATERAL MISALIGNMENT)SIGHT WITH ONE EYE ONLY
ALWAYS USE THE CENTRE (BASE) GAUGESAS YOUR REFERENCE POINT IN DETECTING
ANY MISALIGNMENT
SOMETIMES SIGHTING FROM THE OPPOSITE END
AIDS THE TECHNICIAN WITH A CLEARER VIEW
VIEWING FROM THE OPPOSITE END OF THE VEHICLE
CHECKING THE CENTRE SECTION
IF NO DIMENSIONS ARE AVAILABLE FOR DIAGONALMEASUREMENT, THE FOLLOWING WILL APPLY:
- IN THE CENTRE SECTION, CHECK THE LENGTH ANDWIDTH OF REFERENCE POINTS AVAILABLE
- ONCE VERIFIED EQUAL, SIDE TO SIDE AND END TO END, A CROSS MEASUREMENT CAN BE ACCOMPLISHED
THIS IS AN EXAMPLE OF INCORRECT WIDTHTHAT WOULD CAUSE A PROBLEM WITH A “X”
MEASUREMENT
IT IS POSSIBLE TO USE A STEEL MEASURING TAPETO ACCOMPLISH A CROSS MEASUREMENT,PROVIDING THERE ARE NO OBSTRUCTIONSWHATSOEVER
USE A TRAM BAR WHENEVER POSSIBLE
ON PICKUP TRUCKS THE CENTRE SECTION ISRELATIVELY SMALL
EXTRA PRECAUTIONS SHOULD BE MADE SO AS NOTTO MEASURE OUTSIDE OF THE CENTRE SECTIONOR INACCURATE READINGS WILL OCCUR
CORRECT PROCEDURE
INCORRECT MEASURING
DO NOT USE CAB MOUNTS AS A REFERENCE POINT
DIAMOND FRAME
CENTRELINE MISALIGNMENT RESULTING FROMDIAMOND
TYPICAL
NON-TYPICAL
DIAMOND AND SWAY
THIS SITUATION IS PRECISELY WHY WE CHECKFOR DIAMOND FIRST
- ONCE CHECK FOR DIAMOND IS COMPLETE, INSTALLTHE TWO BASE GAUGES, #2 & #3.- COMPARE THEM FOR PARELLEL TO DETERMINEIF A TWIST CONDITION EXISTS
- IF THE GAUGES ARE NOT PARALLEL, A TWIST EXISTS
CORRECTALIGNMENT
TWISTEDSTRUCTURE
- ALTHOUGH TWIST CAN ONLY EXIST IN THE CENTERSECTION, THE TECHNICIAN CAN ASSUME IT WILLAFFECT THE LEVEL CONDITION OF THE END SECTIONS
REMEMBER, TWIST ONLY EXISTS IN THE CENTRESECTION, ERRORS IN DIAGNOSIS WILL OCCUR
IF THIS THOUGHT PLAN IS NOT FOLLOWED!
DETERMINING DAMAGE IN THE FRONT OR REARSECTIONS
Out of Level
PREDICTABLE AREAS OF DAMAGE
KEY AREAS OF GAUGE PLACEMENT
DO NOT OMIT THIS GAUGEIF FRONTAL IMPACT IS SUSPECT
DO NOT OMIT CROSSMEMBER GAUGE!
This is the correct method
READ # 1B GAUGE TO THE #2 BASE GAUGE,
Correct method ofreading the main cross member to the base gauge
THEN READ THE 1A GAUGE TO THE 1B GAUGE
THIS IS THE CORRECT PROCEDURE
TRUE SWAY: NO OTHER DAMAGE AFFECTS CENTRELINE
NOTICE THE FRONT SECTION IS OUT OF SQUAREAND DAMAGE CAN ONLY BE CORRECTED BY PULLING
LATERALLY
DIAMOND CONDITION WILL AFFECT CENTRELINE ON BOTH ENDS OF THE VEHICLE, HOWEVER THIS IS NOTA SWAY CONDITION SINCE PULLING THE DIAMOND-
WILL CORRECT CENTRELINE. NO CORRECTION FORSWAY WILL BE NECESSARY
RAIL LENGTH / SHORT RAIL• AS ONE SIDE IS SHORTENED BY THE FORCE OF THE COLLISION, IT DISTORTS THE CENTRELINE READINGTOWARD THAT SIDE OF THE VEHICLE.
• AGAIN, THIS IS NOT A TRUE SWAY SINCE PULLINGSTRAIGHT FORWARD TO RESTORE THE RAIL LENGTHWILL CORRECT THE CENTRELINE
OTHER ISSUES THAT CAN CAUSE CENTRELINEMISALIGNMENT
SHORT RAIL, CENTRELINE CORRECTION PROCEDURE
Note Gauge Position
Correct DatumCorrect Datum
NOTE GAUGE POSITION ON FIRST GAUGE
Incorrect datumIncorrect datum
SUSPENSION / CROSSMEMBER / CRADLE MUST BEGAUGED AND BE LEVEL WITH THE BASE OF THE
VEHICLE
ANOTHER CRITICAL AREA TO BE GAUGED ISAT THE LOWER CONTROL ARM MOUNTING POINTS
MANY NEW VEHICLES HAVE A SUB-FRAME ASSEMBLYTHAT CAN SUSTAIN DAMAGE OR MOVEMENT DURING
A FRONTAL IMPACT
THIS REQUIRES GAUGING AND MEASURING PROCEDURES BE PERFORMED TO ENSURE CORRECT
ALIGNMENT OF THESE MEMBERS TO THE UNIBODYSTRUCTURE
IF A VEHICLE UTILIZES STRUT TYPE SUSPENSION,GAUGING OF THE STRUT TOWERS IS NECESSARY
CENTRELINE AND LEVEL ARE CRITICAL
CENTRELINE AND LEVEL ARE VERY IMPORTANT
THE CROSSMEMBER PIN, ONCE INSTALLED, WILL ACT AS A GUIDE FOR COMPARING CENTRELINE TO THE
SELF CENTERING GAUGES
IT IS IMPORTANT FOR THE SUSPENSION MOUNTING POINTS TO BE IN THE RIGHT LOCATION IN REGARDS TO DATUM
WIDTH AT THE SUSPENSION MOUNTING POINTS ISANOTHER IMPORTANT AREA OF MEASURMENT
THIS CAN BE A DIFFICULT AREA TO DIAGNOSE, ANDA TRAM GAUGE WITH LONG POINTERS MAY BE THE
RIGHT TOOL
USING THE STRUT TOWER GAUGE AS A TOOL FORMEASURING LOWER BALL JOINTS ON A STRUT TYPE
SUSPENSION.
USING THE CENTER PIN, MEASURE LEFT AND RIGHT BALL JOINT LOCATIONS OFF OF THE PIN, THIS WILLHELP ESTABLISH SAI (STEERING AXIS INCLINATION)BETWEEN THE UPPER AND LOWER STEERING AXIS
POINTS
MEASURING LOWER BALL JOINT LOCATIONSHOULD ALWAYS BE PERFORMED IN ANY FRONTALCOLLISION.
ONCE CHECKED FOR LENGTH, CROSS MEASURE.
FULL FRAME
THE SAME PROCEDURE GOES FOR SUB FRAMEMOUNTED SUSPENSION, CHECK LOCATION OFBALL JOINTS, LENGTH AND CROSS.
SEVERE IMPACT TO ONE SIDE OF THE VEHICLECAN RESULT IN A TWISTED CROSSMEMBER
AGAIN, THIS IS WHY INSTALLATION OF GAUGESIN THE CROSS MEMBER AREA IS IMPORTANT TO A PROPER REPAIR PROCEDURE
PROPER INSTALLATION OF GAUGES TO DETECTCROSSMEMBER DAMAGE
EFFECTS OF
REAR IMPACT HAS CAUSED DATUM MISALIGNMENT•REAR SECTION IS BELOW DATUM HEIGHT AND THEWHEELHOUSE ARCH IS ABOVE
INERTIAL FORCES DEFLECTION THROUGHOUT VEHICLE, RESULTING IN DIRECT AND INDIRECT
DAMAGE
RESULTING DAMAGE IS EVIDENT AFTER THOROUGHGAUGING
IN THIS CASE, THE REAR IMPACT IS TYPICAL WHILETHE FRONT SECTION SUSTAINED VERTICALDEFLECTION RESULTING IN DATUM MISALIGNMENT
TYPICAL DEFLECTION IN A REAR COLLISION
TYPICAL CROSS MEASURING AREAS WHEN CHECKINGUPPER BODY DIMENSIONS
UPPER BODY DIMENSIONS CAN COME FROM SOURCESSUCH AS REPAIR MANUALS, OR BE REFERENCED FROMKNOWN STRUCTURAL AREAS OF THE VEHICLE SUCH AS
SEAT BELT MOUNTING POINTS ETC.
Upper Body Dimension ChartUpper Body Dimension Chart
STRUT TOWER MOUNTING GAUGE CAN BE USEFUL IN MANY LOCATIONS OF THE VEHICLE
EXAMPLE OF DAMAGE ANALYSIS SHEET
Measurement Measurement TrackingTracking
• Benefits– Completely assess
damage – Ability to monitor
progress– Determine pulling
direction– Results in a more
accurate repair
Mitchell System Damage Report
Mitchell System Tram Dimensions Chart
Wedge Clamp Diagnostic SheetWedge Clamp Diagnostic Sheet
By Using a DiagnosticSheet, You canEstablish a RepairPlan
Hein WernerHein WernerDimension SheetDimension Sheet
DingerDinger HoopedHooped
Mitchell System Upper Body Dimensions Chart
MitchellMitchellCD systemCD system