RATTLE FROM 'B' PILLAR CAB MTS CUSHION AREA-SERVICE PROCEDURE

Subject: RATTLE FROM "B" PILLAR CAB MOUNT CUSHION AREA (SERVICE PROCEDURE)

Model and Year: 1991 C/K TRUCKS

Some 1991 C/K trucks may experience a rattle from "B" pillar cab mount cushion area.

SERVICE PROCEDURE:

To correct this condition it is necessary to increase torque on the cab body and radiator support mounts to the following revised torque specifications.

1. Body mount bolt (P/N 15611432) from 60-90 N.m. (44-66 lbs.ft.) to 75-95 N.m. (55-70 lbs.ft.)(Figure 1).

2. Radiator support mount (P/N 15538569) from 40-55 N.m. (30-40 lbs.ft.) to 50-63 N.m. (37-46 lbs.ft.)(Figure 2).

The revised torque specifications started with the following VIN breakpoints:

Ft. Wayne ASM CHEVY: 1GCDC14K0MZ168782 GMC: 1GTDC14K7MZ519221

Oshawa ASM CHEVY: 2GCHC39N1M1191836 GMC: 2GTEC19KXM1532020

Pontiac East ASM CHEVY: 1GBGC24J4ME175532 GMC: 1GTGK24K9ME527656

Use the most applicable Labour Operation and Time from the Canadian Labour Time Guide.

FIGURE 1-BODY MOUNT SUPPORT

RECOMMENDED, TIGHTENING SEQUENCE

1. (REGULAR CAB) LEFT SIDE BODY MOUNT 01 (FRONT) AND 02 (REAR) MUST BE TIGHTENED IN THIS ORDER. 2. (EXTENDED CAB) LEFT SIDE BODY MOUNT 01 (FRONT) AND 03 (REAR) MUST BE TIGHTENED IN THIS ORDER. 3. ALL RIGHT HAND BODY MOUNTS AND (EXTENDED CAB) BODY MOUNT 02 ARE TO BE TIGHTENED LAST.

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.