Suspension - Noise In Rear Spring
89Chevy24GMC NUMBER: 89-T-91
GROUP: 3D - Rear Suspension
DATE: August, 1989
CORPORATE
NUMBER: 863401R
SUBJECT: REAR SPRING NOISE
MODELS: 1988-89 C1-2, K1-2
This bulletin cancels and replaces GMC Truck Service Bulletin 88-T-163, dated September, 1988 to add the 1989 Model Year, the new part number, and to clarify the source procedure. All copies of 88-T-163 should be discarded.
Some 1988 C1-2 and K1-2 models may experience a noise from the rear leaf springs. This noise is more noticeable on rough roads. The cause of the noise is a metal to metal contact between the main leaf spring pack and the lower leaf spring. This condition can be corrected by installing an insulator on the lower leaf spring. The modulator fits on the tip of the leaf and should be installed with a rubber mallet. It may be necessary to raise the vehicle by the frame to install the inserts. A strip of plastic nylon is attached to one side of the insert. This side should face up toward the remaining spring leaves.
Parts Information
Part Number Model Quantity
15604174 C1, K1 4
15604175 C2, K2 without 8600 GVWR 4
15604176 C2, K2 with 8600 GVWR 4
15604176 C3, K3 4
Parts are expected to be available on September 14, 1989. Until then normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP srcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while the 400 control is in place.
For vehicles repaired under warranty, use:
Labor Operation: T7760
Labor Time: .3 Hr