G 30 1 Ton Van V8-379 6.2L DSL VIN J FI (1984)
Suspension Spring ( Coil / Leaf ): All Technical Service Bulletins
Suspension, Front - Bottoming
Number:
86-106
Section:
3C
Date:
July 1986
Subject:
FRONT SUSPENSION BOTTOMING
Model and Year:
1983-86 G-20,30 MODEL VANS WITH 6.2L (VIN CODE C OR J) DIESEL ENGINES
TO:
ALL CHEVROLET DEALERS
On some G20 and G30 model Vans equipped with 6.2L diesel engines (VIN Code C OR J), a condition may exist where the rubber
jounce bumper becomes very hard in low ambient weather and 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. 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 terrains. The Service Procedure for installing the air cylinders is as follows:
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.
FIGURE 1 - AIR CYLINDER SHOWN INSTALLED IN FRONT COIL SPRING
3.
Install the air cylinder inside the coil spring so that the protector plate is toward the upper control arm. This will allow the
schrader valve to protrude through the hole in the lower control arm. (See Figure No. 1).
4.
Install the coil spring by following the procedure in Section 3C Front Suspension, in the Light Duty Service Manual.
5.
For most driving conditions, the air pressure should be maintained between 310 kPa (45 psi) minimum and 345 kPa (50 psi)
maximum.
6.
Air pressure in these cylinders may be increased or decreased to adjust vehicle trim and minimize jounce bumper impact on
