Pinpoint Tests
Suspension System
Pinpoint Tests
Pinpoint Test A: Vehicle Drifts/Pulls
This pinpoint test is intended to diagnose the following:
- Unevenly loaded vehicle
- Tire pressure
- Tire forces
- Brake drag
- Incorrect vehicle alignment
- Steering system
PINPOINT TEST A: VEHICLE DRIFTS/PULLS
-------------------------------------------------
A1 CHECK FOR UNEVENLY LOADED VEHICLE
- Visually check the vehicle for an uneven loading condition.
- Is the vehicle unevenly loaded?
Yes
ADVISE the customer of uneven loading condition.
No
GO to A2.
-------------------------------------------------
A2 CHECK THE TIRE PRESSURES AND TIRE CONDITIONS
- Check the tire pressures. Refer to the VC label located on the driver door jamb. Check the tires for uneven/abnormal wear. Refer to Diagnosis and Testing - Wheels and Tires in Wheels and Tires Testing and Inspection.
- Are the tire pressures and tire conditions OK?
Yes
GO to A3.
No
ADJUST the tire pressures to the specified pressure or INSTALL new tires as necessary.
-------------------------------------------------
A3 ISOLATE TIRE DRIFT/PULL CONDITION
- NOTE: It is important to determine if tire forces are the cause of a drift/pull condition. Changing the position of the wheel and tire assemblies on the vehicle may correct a pull/drift condition. A tire or tires that are causing a drift/pull should not be removed from service unless it has been determined that the tire(s) are worn beyond specification. Refer to Diagnosis and Testing - Wheels and Tires in Wheels and Tires Testing and Inspection
- Cross the front wheel and tire assemblies from left-to-right. Refer to Wheels and Tires Removal and Replacement.
- Does the vehicle drift/pull?
Yes
If the vehicle drifts/pulls in the opposite direction, tire forces are causing the drift/pull. ROTATE the wheel and tire assemblies front-to-rear. REFER to Wheels and Tires Removal and Replacement. If the vehicle drifts/pulls in the same direction, GO to A4.
No
Tire forces were causing the drift/pull and the concern has been corrected.
-------------------------------------------------
A4 CHECK SUBFRAME ALIGNMENT
- Using the subframe alignment tool 205-870, check the subframe alignment.
- Is the subframe aligned correctly?
Yes
GO to A5.
No
Remove and discard the 2 rear subframe bolts, loosen the 2 front subframe bolts and using the subframe alignment tool 205-870 align the subframe. Tighten the 2 front subframe bolts to 60 Nm (44 lb-ft). Tighten the 2 new rear subframe bolts to 100 Nm (74 lb-ft), then tighten an additional 240°.
Vehicle wheel alignment must be reset after the subframe is moved. ADJUST the alignment as necessary. REFER to General Procedures.
-------------------------------------------------
A5 CHECK FOR BRAKE DRAG
- Spin all four wheel and tire assemblies by hand and check for brake drag.
- Do the wheels spin freely?
Yes
GO to A6.
No
REFER to Brake System - General Information Testing and Inspection to diagnose brake drag condition.
-------------------------------------------------
A6 CHECK THE WHEEL ALIGNMENT
- Using alignment equipment and the manufacturer's instructions, check the wheel alignment.
- Is the wheel alignment out of specification?
Yes
ADJUST the alignment as necessary. REFER to General Procedures.
No
REFER to Steering System Testing and Inspection to diagnose steering system drift/pull/wander condition.
-------------------------------------------------