Some 1991 C/K trucks may experience a rattle from "B" pillar cab mount cushion area.
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 1GCDC14K0MZ168782 Oshawa ASM 2GCHC39N1M1191836 Pontiac East ASM 1GBGC24J4ME175532
For vehicles repaired under warranty use: Labor Operation: T7291 Labor Time: 0.2 hrs
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.