G 3500 1 Ton Van V8-454 7.4L (1989)
Suspension Spring ( Coil / Leaf ): All Technical Service Bulletins
Suspension, Front - Bottoming Out Noise
BULLETIN NUMBER: 93-3-65
SECTION: 3
NUMBER: 1
CORPORATE REFERENCE NUMBER: 163301R
DATE: April 1993
SUBJECT:
FRONT SUSPENSION BOTTOMING NOISE (INSTALL AIR CYLINDER)
MODELS:
1983-93 G2 AND G3 VANS WITH 4.3L, 5.0L, 5.7L, 7.4L AND 6.2L ENGINES
THIS BULLETIN CANCELS AND REPLACES GMC TRUCK SERVICE BULLETIN # 91-3C-130 AND IS BEING REVISED TO INCLUDE THE
1992 AND 1993 MODEL YEARS.
CONDITION/CAUSE
On some 1983-93 G2 and G3 model vans equipped with 6.2L diesel engines (RPO LL4 or LH6) and gas engines (RPO LB4, L03, L05, or L19) a
condition may exist where the rubber jounce bumper makes an impact sound when it contacts the stop surface of the crossmember. This condition will
usually be experienced on a vehicle traveling over large road bumps with capacity loads and sometimes at low temperatures.
CORRECTION
To correct this condition, urethane air cylinders (P/N 367762 - two required) may be installed inside the front coil springs. These air cylinders will help
to cushion the front suspension on rough terrain.
SERVICE PROCEDURE
1.
Follow the coil spring removal procedure in Section 3C Front Suspension, in the Light Duty Service Manual.
2.
Clean the lower spring seat area of all rust where the air cylinder will seat.