FRONT SUSPENSION SQUEAK INSTALL 'M' VAN INSULATORS

SUBJECT: FRONT SUSPENSION SQUEAK

MODELS: 1982-91 S LIGHT DUTY TRUCK

THIS BULLETIN CANCELS AND REPLACES GMC TRUCK SERVICE BULLETIN 91-3C-56, DATED JANUARY, 1991 TO CHANGE THE LABOR OPERATION AND LABOR TIME. ALL COPIES OF 91-3C-56 SHOULD BE DISCARDED.

Some S1 trucks may experience a squeaking noise from the front suspension. Spraying of lubricant in the spring pocket areas may help for a short time but the squeak usually returns.

The usual cause of this squeak is contact between the spring and the frame pocket or control arm. An insulator is installed in production between the spring and upper frame pocket but this insulator will occasionally be pushed aside allowing metal to metal contact. An insulator was not installed in production between the control arm and the spring.

To fix the squeak, the existing upper insulator should be removed and M-Van insulators installed at both ends of the spring between the spring and the upper frame pocket and between the sporing and the lower control arm.

VEHICLES INVOLVED

1982-1991 S trucks

SERVICE PROCEDURE

Remove:

1. Lower control arm and spring. 2. Insulator from top end of spring. - Clean excess paint and adhesive form both ends of spring.

Install:

1. New insulators to spring ends - Apply a full bead of weatherstrip adhesive to the diameter of the spring/insulator contact area.

- Be sure upper and lower insulator are installed to respective ends of the spring.

- Allow weatherstrip adhesive to cure enough to hold the insulators in place before reinstalling springs.

2. Spring - Tape should be on lower end and gripper notch on top.

- Position end of lower spring coil to cove one lower control arm inspection drain hole and expose the other hole.

3. Lower control arm.

Refer to S/T Service Manual, Section 3C - Front Suspension for complete coil spring replacement procedure.

SERVICE PARTS INFORMATION

Part Quantity Number Description Required ---------- -------------------------- --------- 15522278 Insulator, Front Spring Upper 2 15522279 Insulator, Front Spring Lower 2 12345097 Adhesive, Weatherstrip, 5 oz. 1

Parts are currently available from GMSPO.

WARRANTY INFORMATION

For vehicles repaired under warranty use: Labor Operation: E3907 Labor Time: 1.5 hr.

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.