C 3500 Truck 2WD V8-379 6.2L DSL (1988)
Torsion Bar: All Technical Service Bulletins
Suspension - Torsion Bar Adjustment
Number:
88-131-3A
Section:
3A
Date:
Jan., 1988
Subject:
TORSION BAR ADJUSTMENT
Model and Year:
1988 K-1500, 2500, 3500 MODELS
TO:
ALL CHEVROLET DEALERS
1988 K models which are intended for snow plow applications may require front suspension option F60. When F60 is ordered, the vehicle's base torsion
bars are upgraded to the next higher rate bars to compensate for vehicle trim changes due to the extra weight of the snow plow assembly. Vehicles that
were built with Z71 off road chassis package were equipped with F60 as part of the Z71 package.
Some vehicles equipped with base level torsion bars may only require minor trim height changes to be adaptable for snow plow applications. Variations
in the assembly plant build and torsion bar settings may allow for additional trim height changes which can be made by adjusting the torsion bars. On
vehicles built before the VIN breakpoints provided on page 2, it is not recommended that the torsion bars be adjusted more than four or five times.
Vehicles built after the breakpoints can be adjusted multiple times without detrimental effects on the adjustment mechanism. Those vehicles equipped
with base level torsion bars requiring additional trim height beyond that which is attainable through a trim height adjustment must have the F60 torsion
bars installed in place of the base bars.
To determine which torsion bar is installed in the vehicle, the three digit code stamped on the end of the bar must be noted. These three digits are the last
digits of the part number, which can be found in the base production torsion bar chart listed on page 2. To determine the correct F60 bar to be used, the
part number from the base production torsion bar side of the chart must be cross referenced to the corresponding F60 torsion bar on the right half of the
chart.
When replacing or adjusting torsion bars, follow the procedure in Front Suspension and Axle, Section 3C of the 1988 C/K Service Manual. The front
suspension alignment specifications, for vehicles which have had F60 installed at the dealer level are provided on the chart. Most vehicles which have
F60 installed will not require caster and camber adjustments, however, toe-in must be set at "0" degrees at vehicle curb trim.
VIN Breakpoints:
Fort Wayne
Chevrolet
JZ186298
Pontiac
Chevrolet
JE153765
Oshawa
Chevrolet
J1199957
Adjustment or replacement of torsion bars to compensate for vehicles not equipped with F60 (snow plow package) is not covered under the terms of the
New Vehicle Warranty.
K TRUCK TORSION BAR USAGE
Base Production Torsion Bar K-1500
Left P/N
Right P/N
15528951
15528952
15528955
15528956
15528959
15528960
15528963
15528964
K-2500-3500
Left PIN
Right P/N
15528953
15528954
15528957
15528958
15528963
15528964
15528965
15528966
F60 Torsion Bar K-1500
Left P/N
Right P/N
15528955
15528956
15528959
15528960