RATTLE NOISE FROM REAR FRAME CROSSMEMBER-NEW PARTS RELEASED. GMC Truck S15 Pickup - 4WD 1988

For 1990-2009 cars

# RATTLE NOISE FROM REAR FRAME CROSSMEMBER-NEW PARTS RELEASED

#### SUBJECT: RATTLE NOISE FROM REAR FRAME CROSSMEMBER (REPLACE CROSSMEMBER) * (Revised to Remove Warranty Information on Page 3)

#### VEHICLES AFFECTED: 1988-90 T1 UTILITY VEHICLES

Separation of the rear shock absorber tower from the frame crossmember in 1988-90 T Utility Vehicles may result in the driver noticing a rattle noise coming from the rear of the vehicle over bumps. If the rear shock tower separates from the frame crossmember, the entire rear frame crossmember and tower assembly should be replaced using the following parts and service procedures. The new crossmember has reinforced shock absorber towers.

#### Service Procedures:

1. Disconnect battery ground cable. 2. Raise vehicle on hoist. 3. Remove the six bolts holding the fuel tank protective shield on and remove shield. 4. Remove fuel tank, refer to Figure 1.

A. Drain fuel from tank through the filler neck using a hand pump or energize in-tank fuel pump and drain from fuel feed line. See service manual for proper procedures and safety precautions. B. Remove lines and disconnect fuel fill hose and vent hose. C. Support fuel tank and remove tank supports (5). D. Lower tank sufficiently to disconnect sender unit connector. E. Remove fuel tank. F. Remove front bolts from tank upper straps and move straps to rear out of the way.

5. Remove shock absorbers as shown in Figure 2. A. Remove shock absorber to tower bolts and nuts. B. Remove shock absorber to anchor plate nut and washer. C. Remove shock absorber from vehicle.

6. Remove rear frame crossmember and towers, refer to Figure 2.

A. Cut three crossmember to frame rivet heads off on each side of vehicle. Use air chisel, cutting wheel, or grinding wheel.

B. Remove and discard crossmember and tower assembly. Before discarding, remove the two spring mounted nuts for the tank straps and install the nuts in the new crossmember.

7. Install new frame crossmember and tower assembly (Figure 2).

A. Install three bolts, nuts, and six washers on each side of frame crossmember and torque nuts to 40-51 N.m (29-37 lbs. ft. or torque bolts to 45-60 N.m (33-44 ft.lbs.).

B. Reinstall shock absorber and torque anchor plate nut to 20-26 N.m (15-19 ft.lbs.).

C. Bolt shock to tower and torque nuts to 58-70 N.m (43-50 ft.lbs.).

8. Reinstall fuel tank, refer to Figure 1.

A. Raise tank sufficiently to install fuel tank sending unit hoses, electrical connector, and ground strap. Route strap 1 under hoses and wiring.

B. Raise tank fully and install tank supports (5). Torque front strap nuts (9) to 27-47 N.m (20-35 ft.lbs.). Torque support nuts (7) to 40-50 N.m (29-37 ft.lbs.).

C. Reinstall tank shield and torque screws to 9-13 N.m (80-115 in.lbs.).

9. Lower vehicle, refill fuel, connect battery negative ground cable.

10. Start engine and check for fuel leaks.

#### SERVICE PARTS INFORMATION

Part Number Description Quantity ----------- ------------------- --------- 15674914 Rear Frame Crossmember and Shock Tower 1 Assembly 11504596 Bolt, Crossmember Mounting, 6 11501033 Nut, Crossmember Mounting, 6 15531204 Washer, 12

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.