TSB From A Pontiac Bonneville

Steering - Steering Column Clunk Felt/Heard on Turns

Bulletin No.: 06-02-35-010

Date: May 09, 2006

TECHNICAL Subject:
Clunk Felt/Noise Heard From Steering Column, Steering Gear and/or Front of Vehicle During Maneuver and/or Steering Wheel Rotation (Replace Intermediate Shaft)

Models:
2001-2004 Cadillac Seville - with RPO JL4
2001-2003 Oldsmobile Aurora
2000-2005 Pontiac Bonneville

Attention: This bulletin ONLY applies to the above listed vehicles. All other cars with a similar condition should refer to Corporate Bulletin Number 01-02-32-001G.

Condition:

Some customers may comment on a clunk type noise coming from the front of the vehicle while driving during a turning maneuver. This condition may also be felt through the steering wheel when the vehicle is stationary and the wheel is rotated from steering stop to steering stop. Some vehicles may only exhibit the noise once for every 360°of wheel rotation. On all other vehicles, this clunk noise will be noticed during low speed acceleration or deceleration, typically in light turns of the steering wheel.

Cause:

This condition may be caused by inadequate lubrication of the steering intermediate shaft which results in a slip stick condition possibly resulting in the clunk noise.

Diagnostic Tip
Important: This condition is commonly misdiagnosed as originating in the steering gear and has resulted in the replacement of numerous steering gears without correcting the concern.

Engineering Investigation shows that numerous steering gears have been misdiagnosed and replaced. The investigations shows that if the technician incorrectly diagnoses the steering gear as the cause of the noise and/or clunk during replacement of the steering gear, the technician may stroke and/or cycle the I-shaft, distributing the original grease in the I-shaft. This distribution of the original I-shaft grease temporarily may eliminate the I-shaft clunk so that the technician believes the noise and/or clunk is corrected with the steering gear replacement and returns the vehicle to the customer. After the customer drives the vehicles for several miles and dissipates the original grease, the noise may return.

Attempt to duplicate the customer's concern and isolate the I-shaft by following the procedure below:
1. Locate a large area (parking lot) where the vehicle can be turned in a tight circle.

2. Turn the steering wheel to the right and/or left all the way to the steering lock, then off the steering lock a 1/4 turn.

3. Drive the vehicle approximately 5 km/h (3 mph) in a circle, preferably over rough pavement or seams on the road surface.

4. If a clunk is felt in the steering wheel, the MOST likely cause is the I-shaft - not the steering gear. Continue with the correction.

Correction
Important: The replacement steering intermediate shaft is physically different in appearance than the original. However, the vehicle's ride performance will not be affected.

Replace the original concentric style steering shaft with P/N 26068295, a Double "D" design. Refer to Intermediate Steering Shaft Replacement in SI.