NOISE ON TURNS OR SLAPPING SO. OVER BUMPS-INS. BRKT.&BUSHINGS

SUBJECT: NOISE ON TURNS OR SLAPPING SOUND OVER BUMPS (INSTALL BRACKETS AND BUSHINGS)

MODEL: 1985-1993 G3 VANS

CONDITION

Owners of some 1985-93 G3 model vans, may comment that the vehicle makes noise on turns, or has a slapping sound while driving over bumps.

CAUSE

This may be caused by the front stabilizer bushing at the lower control arm working its way out of the mounting clamp. This condition occurs due to limiting stack conditions when the working angles of the stabilizer bar (frame to lower control arm relationship) cause forces which will work the bushing out of the control arm mounting clamp.

CORRECTION

To correct this condition, new stabilizer brackets and bushings, located on the frame, can be installed. The new parts will position the stabilizer bar approximately .4 inches lower than the existing parts.

The new stabilizer brackets and bushings were used on vans starting with the following VIN breakpoint:

GMC Truck PF516028

SERVICE PROCEDURE

REMOVAL:

------- 1. Raise the vehicle and support with suitable safety stands.

2. Remove the tire and wheel assembly.

3. Remove the bolts (54), the washers, and the brackets (52).

4. Remove the stabilizer shaft (59) from the frame.

5. Remove bolts (43), nuts (38), washers (39 & 41), and brackets (42).

6. Remove the stabilizer shaft (59) from the lower control arm (36).

7. Remove the bushings from the stabilizer shaft (40 & 53).

Note: Inspect the bushings at the lower control arm (40) for excessive wear, deterioration, or other damages, replace if needed. Discard the bushings (53) that were removed from the frame brackets.

INSTALLATION:

------------ Note: When fasteners are removed, always re-install them at the same location from which they were removed. ff the correct fastener is damaged or not available, use a fastener of equal size or strength (or stronger). Use the correct torque values on all fasteners. If the above conditions are not followed, parts or system damage could result.

1. Install bushings (40 and the new bushings 53) to the stabilizer shaft (59).

Note: It may be necessary to clean the shaft from dirt and other contaminants. Use rubber lubricant to help slide the bushings onto the shaft.

2. Install stabilizer shaft (59) to the vehicle.

3. Install the new brackets (52), bolts (54), and washers (55).

4. Install brackets (42), bolts (43), washers (39 & 41), and nuts (38).

Torque Specs:

Nuts (38): 29 N-m (21 lbs. ft.).

Bolts (54): 33 N-m (24 lbs. ft.).

5. Install tire and wheel assembly.

6. Remove the support stands and lower the vehicle.

SERVICE PARTS INFORMATION

Part Number Description Qty. ------ ----------- ---- 15964469 Insulator-frt stab. shaft 2 15964471 Clamp-frt stab. shaft insl 2

Parts are currently available from GMSPO.

WARRANTY INFORMATION

For vehicles repaired under warranty, use:

Labor Op Description Labor Time ----- ----------- ---------- E2147 Link and/or bushing and/or See Applicable bracket front stab shaft at Labor Time control arm Guide

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.