Idler Arm Inspection

Special Tools

• J 35999  Spring Scale
• J 42640 Steering Column Anti-Rotation Pin
• J 45101  Hub and Wheel Runout Gauge

1. Raise the vehicle on a hoist and support it with jackstands. Refer to Lifting and Jacking the Vehicle .
Fig 1: Locking/Unlocking Steering Column
Courtesy of GENERAL MOTORS CORP.
CAUTION:

With wheels of the vehicle facing straight ahead, secure the steering wheel utilizing steering column anti-rotation pin, steering column lock, or a strap to prevent rotation. Locking of the steering column will prevent damage and a possible malfunction of the SIR system. The steering wheel must be secured in position before disconnecting the following components:

• The steering column
• The intermediate shaft(s)
• The steering gear

After disconnecting these components, do not rotate the steering wheel or move the front tires and wheels. Failure to follow this procedure may cause the SIR coil assembly to become un-centered and cause possible damage to the SIR coil. If you think the SIR coil has became un-centered, refer to your specific SIR coil's centering procedure to re-center SIR Coil.

2. Position the wheels straight-ahead and install anti-rotation pin J 42640 .
3. Install runout gauge J 45101  between the idler arm and the vehicle frame.

   Ensure the runout gauge is at zero before taking the measurement.

Fig 2: Placing Special Tool Near Relay Rod End Of Idler Arm
Courtesy of GENERAL MOTORS CORP.
4. Place scale J 35999  near the relay rod end of the idler arm.
Fig 3: Measuring The Upward Force
Courtesy of GENERAL MOTORS CORP.
5. Exert a 110 N.m (25 lb) force upward and then downward while measuring the total distance the idler arm moves.
Fig 4: Measuring Idler Arm Movement
Courtesy of GENERAL MOTORS CORP.
6. If the movement exceeds 2 mm (0.078 in) then replace the idler arm.
Fig 5: View Of Dial Indicator At Idler Arm
Courtesy of GENERAL MOTORS CORP.
7. Install the runout gauge at the idler arm.
8. Push the tire inward slowly with one hand to remove any lash.

   Zero out the runout gauge and pull outward in order to take a reading.

Fig 6: Measuring Idler Arm Movement
Courtesy of GENERAL MOTORS CORP.
9. Allow only 1 mm (0.039 in) of movement at the idler arm ball stud.

   If the movement is more than 1 mm (0.039 in) then replace the idler arm.