Lubricate the steering linkage with EP chassis lubricant GM P/N 12377985 or the equivalent, meeting GM-NLGI#2, category LB or GC-LB specification, whenever inspection or work is done on the steering linkage, and at intervals specified in the maintenance schedule in Maintenance and Lubrication.

Replace damaged or broken steering linkage components. NEVER attempt to repair these components.

Inspection Procedure

1. Set the wheels in the straight ahead position.
2. Set the steering wheel into the locked position.
3. Raise the vehicle on 1 side so the tire is 25 mm (1 inch) off the floor.
4. Position a dial indicator at the edge of the wheel rim.
5. Move the wheel back and forth without using the steering wheel. Ensure that the gauge does not exceed 6.74 mm (0.108 inch).
6. If the gauge reading exceeds specifications, inspect all linkage pivots and ball studs for looseness and replace where necessary.

Inspection Procedure

Important: 

•	Jerking the right wheel and the tire assembly back and forth in order to cause an up and down movement of the idler arm is NOT an acceptable test procedure. You cannot control the force applied to the idler arm.

•	Loose idler arms, or other suspension steering system conditions can create a shimmy. Shimmy may originate at the wheel and tire assembly from dynamic imbalance, runout or force variations, or even road surface irregularities. Consider all possible causes of shimmy complaints.

1. Raise and support the vehicle.
2. Ensure that the front wheels rotate freely, the steering mechanism turns freely, and the wheels are positioned straight ahead. Refer to Lifting and Jacking the Vehicle in General Information.
3. Position a dial indicator against the top of the idler arm grease cap.
4. Place a spring scale near the relay rod end of the idler arm.
5. Apply a 110 N (25 lb ft) force forward.
6. Apply a 110 N (25 lb ft) force rearward.
7. Measure the total distance the idler arm moves under the applied force.

A limit of no more than 3.2 mm (1/8 inch) deflection in each direction, for a total of 6.3 mm (1/4 inch) is allowed.

8. Replace the idler arm if the idler arm fails the test. Refer to Idler Arm Replacement