PICKUP BOX 'OIL CANNING' CAUSED BY WELDS SEPARATING

MODELS: 1988 C/K

Some 1988 C/K models may develop an "oil canning" sound from the pickup box area. This sound may be caused by welds separating between the pickup box bed and cross sill areas (See Figure No. 1). There are six cross sills in total. The condition can be verified by walking across the bed and listening for the oil canning sound or by visually looking for separated welds from under the vehicle. To repair this condition, the following procedure should be used:

o Drill each affected spot weld with a 5/16" drill bit.

Note: Do not drill through cross sill.

o Clean the area between the bed and cross sill of dirt.

o Sand or grind around each spot weld affected to remove all paint from an area 1/2" around the weld.

o Mig weld each drilled area using .023" diameter steel wire.

o Grind each weld smooth.

o Refinish the affected areas.

Vehicies built between the following VIN break-points may be affected by this condition.

OSHAWA

GMC 2GTCC14K2Jl5OO396 2GTDK14K7J1500630 Chevrolet 2GCDC14Z5J1101161 2GCDC14Z7J1102358

PONTIAC EAST

GMC 1GTDC14H8JE5002952 1GTDK14HXJE5003962 Chevrolet 1GCDC14Z2JE1006931 1GCDC14K4JE1013771

FORT WAYNE

GMC 1GTDC14H3JZ500150 1GTDC14H9JZ500332 Chevrolet 1GCDC14Z1JZ100502 1GCDC14HXJZ100943

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.