B Thud/Clunk Noise

(B) THUD/CLUNK NOISE

CONDITION: I
Thud/Clunk noise from rear of vehicle most apparent after a harsh/sharp road input such as a chuck-hole/speed bump (1988-91 vehicles with auxiliary springs).

CAUSE:
Auxiliary rear spring lower attaching bracket not in full contact with rear spindle rod.

CORRECTION:
Insure auxiliary rear spring lower brackets are properly seated on spindle rods (Reference Bulletin # 91-3D-1).


CONDITION: II
Clunk from rear of vehicle noted during normal suspension/vehicle movements. (1988-90 vehicles)

CAUSE:
Exhaust system contacting rear stabilizer shaft.

CORRECTION:
Inspect exhaust system and stabilizer shaft for witness marks due to metal-to-metal contact. Align exhaust system to provide adequate clearance if interference condition is noted.


CONDITION: III
Thud from rear of vehicle noted during extended suspension movement. Condition most apparent when vehicle is turning up parking ramp/driveway or driven over deep chuck-hole or speed bump (1988 and early 1989 vehicles).

CAUSE:
Rear struts extend to their maximum travel. Not detrimental to struts but associated noise may be cause of annoyance.

CORRECTION:
Replacement of both rear struts and spring plates with interim 1989 components provides additional 10 mm of travel. Component replacement will reduce the potential for occurrence of this condition but may not eliminate it completely and is inherent to suspension design (Reference Bulletin # 89-3-11A).


CONDITION: IV
Thud/clunk from rear of vehicle after a harsh/sharp road input such as a chuck-hole/speed bump. (1988-92 vehicles)

CAUSE:
Spindle rod bushing(s) loose in the spindle rod. Spindle rod cross section appears somewhat collapsed at open ends.

CORRECTION:
Replace spindle rods.

Base Suspension Up Level Suspension

P/N 10062855 (Front) P/N 10062857 (Front)
P/N 10152146 (Rear) P/N 10152147 (Rear)

Parts are currently available from GMSPO.