PICKUP BOX RATTLE AT FRONT PANEL AND SIDE PANEL JOINT

VEHICLES AFFECTED: 1988 C/K MODELS

Some 1988 C/K models may develop a rattling sound from where the pickup box front and side panels join together. To eliminate this condition, a service procedure has been developed to weld a portion of the pickup box side panel to the pickup box front panel.

Service Procedure

- Disconnect n(igative battery cable.

- Remove bolts holding the neck of the fuel filler tube to the side panel.

- Raise and support the vehicle.

- Disconnect taillamp wiring harness and ground strap at frame rail.

- Remove eight bolts holding box to the frame rails.

- Slide box rearward on frame rails to get enough access to work on the front end panel. Support back of box.

Welding and Metal Finishing

- Using a knife or pointed tool, remove all sealer and aluminum shims where the front panel fits into the side panels (Figure 1). Failure to remove all sealer will result in weld splatter or pitting.

- Remove paint down to bare metal, approximately 1/2", where the front panel fits into the side panel as shown in Figure 1.

- Isolate the repair area by draping a drop cloth over the surrounding finished panels and glass to prevent accidental weld splatter.

- To weld the two panels, use a mig welder with 75% argon, 25% C02 or 100% C02 shielding gas and E7OS3 wire (.035" or or .045" diameter).

- Weld a 25mm (I inch) bead securing the front panel to the side panel (Figure 1). It may be necessary to hold these panels together with a "C" clamp to get a good fit.

- Grind the welds flush.

Spot Repair Using Urethane Clear Coat, Figure 2

- Clean involved surfaces with a grease and wax remover (Dupont 3812S enamel reducer or equivalent).

- Feather edge the paint using standard paint preparation procedure.

- Metal prep the bare metal thoroughly (Dupont 5717 metal conditioner or equivalent).

- Mask off the surrounding area and spray on an acrylic primer (Dupont Variprime 615S/616S or equivalent).

- Apply a primer surfacer (Dupont 1315 or equivalent).

- Sand primer with 360 grit dry followed by 400 grit dry. Apply sealer (Dupont Velvaseal 1984S, 1985S, and 1986S or equivalents).

- Apply a paint adhesion promoter and allow to dry (Dupont 222S or equivalent).

- Apply base color coat per label direction for spot repair. Apply urethane clear coat (Dupont 1080S clear urethane, 1082S activator, a.nd 1085S reducer or equivalents) beyond base color coat but within the area of the adhesion promotor. Allow to dry overnight and compound.

Pickup Box Reinstallation

- Reinstall box to frame rails. Torque bolts to 70 Nm (52 lb ft).

- Reconnect wiring harness and ground strap.

- Reinstall and tighten the fuel filler tube to the side panel.

- Reconnect the negative battery cable.

* Use the most applicable labour operation from the Canadian Labour Time Guide and claim 2.6 hours.

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.