STEERING WHEEL OSCILLATION WOBBLE-STEERING GEAR ADJ.REPL.

Subject: STEERING WHEEL OSCILLATION/WOBBLE (STEERING GEAR ADJUSTER SPRING REPLACEMENT)

Model and Year: 1990-91 U-VAN

Condition: Some 1990-91 U-vans may exhibit a condition where the steering wheel may oscillate 5-10 degrees after road inputs, such as a swell/dip or other minor road irregularities. A typical operator's comment may be that the steering wheel wobbles/rocks back and forth or that the vehicle seems to slightly wander, which may be attributed to operator steering inputs made to compensate for wheel oscillation.

Cause: This condition is the result of the additive effects of the following parameters:

- low friction steering - unequal torque induced drive inputs - road induced tire inputs.

Correction: This condition may be corrected by replacement of the existing steering gear adjuster spring with a new higher rate spring, P/N 26030764, following the procedure indicated below:

Service Procedure:

1. Raise vehicle insuring steering wheel is centered.

2. Loosen adjuster plug lock nut (5) and remove adjuster plug (4). Remove adjuster spring (3) and discard.

3. Coat new adjuster spring (3), P/N 26030764 and threads of adjuster plug (4) with lithium grease.

4. Install new adjuster spring (3) and adjuster cap (4). Tighten cap until it bottoms in housing (1), then back off 50 degrees to 70 degrees (approximately one flat).

5. Tighten lock nut to 70 N.m. 150 lbs. ft.) while holding adjuster plug (4) stationary.

6. Lower vehicle and check returnability of the steering wheel to center.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.