Steering - Idler Arm Inspection

9215chevy02

Number: 92-04-3B

Section: 3B

Date: AUGUST 1991

Corporate Bulletin No.: 163303


Subject: IDLER ARM INSPECTION


Model and Year: 1988-91 C/K TRUCKS


Sometimes idler arms on 1988-1992 C/K trucks are checked as part of a routine safety inspection or because of a steering complaint. If the vehicle is being inspected for a shimmy complaint first consider areas such as dynamic imbalance, run out or force variation of wheel and tire assemblies and road surface irregularities, etc.

To avoid the customer dissatisfaction involved in replacing idler arms unnecessarily, use the following idler arm checking procedure.

SERVICE PROCEDURE:

1. Raise the vehicle. Support the vehicle with jack stands. Allow the front wheels to rotate freely and the steering mechanism freedom to turn. Position the wheels in a straight ahead position.

2. Place a spring scale and dial indicator near the relay rod end of the idler arm. Exert a 110 N (25 lbs.) force upward and record dial indicator change before and after upward load application. Then exert 110 N (25 lbs.) force downward and record the dial indicator change before and after downward load application. Add the two deflections due to the upward and downward load, the total allowable deflection is 6.4 mm (1/4-inch). Replace the idler arm if the deflection exceeds this amount.

Important Note: Moving the front wheel and tire assemblies back and forth, causing an up and down movement of the idler arm, is NOT an acceptable testing procedure. There is no control on the amount of force being applied to the idler arm.