OVER EXTENSION OF FRT. SHOCKS NEW TORSION BAR ADJUSTER
VEHICLES AFFECTED: 1988-89 K 1,2,3, W/RPO F60
A 1990 model torsion bar adjusting arm part #15603963 is now available through CANSPO for 1988 and 1989 model trucks equipped with F-60 option that continue to damage front snocks, even after adjusting the torsion bar for the lowest front ride height. This new torsion bar adjusting arm will provide a lower font ride height, thus preventing over extension and damage to shocks, These adjusters will not change Gross Front Axle Weight Rating (GFAWR).
SERVICE PROCEDURE:
REMOVAL PROCEDURE FOR TORSION BAR ADJUSTMENT ASSEMBLIES ON BOTH TORSION BARS (REFER TO FIGURES 1 AND 2).
Tool Required: J36202 - Torsion Bar Unloading Tool
1. Raise vehicle front and support with suitable safety stands.
2. Increase the tension on adjustment arm (186) using J36202.
3. Remove adjustment bolt (184) and retaining plate (185).
4. Release tension on adjustment arm and move tool aside.
5. Slide torsion bars forward.
6. Remove the adjustment arms (186).
REPLACEMENT PROCEDURE FOR NEW TORSION BAR ADJUSTMENT ASSEMBLIES ON BOTH TORSION BARS (Refer to Figures 1 AND 2).
Tool Required: J36202 - Torsion Bar Unloading Tool
1. Fit the new torsion bar adjusting arms (part #15603963) on torsion bars.
2. Increase the tension on the torsion bar, using J36202.
3. Install the retaining plate and the adjustment bolt.
4. Release the tension on the torsion bar until the load is take up by the adjustment bolt.
5. Remove J36202.
6. Lower the vehicle.
7. Reset "Z" height and front end alignment to the specification listed at the end of this bulletin.
SERVICE PARTS INFORMATION:
Part Number Description Quantity
15603963 Torsion bar adjuster 2
SERVICE SPECIFICATIONS:
After installing these adjusters the "Z" height setting and alignment specifications should be reset to the revised 1990 specifications list below:
TRIM HEIGHTS (Z Heights)
Model Z Height
K1, K2-C6P 157.0 mm +/- 6.0 mm K2+C6P, K3 145.0 mm +/- 6.0 mm
ALIGNMENT SPECIFICATIONS (K1,2,3)
Model Camber Cross Camber
K1, K2-C6P 0.65 degrees +/- 0.5 degrees 0.5 degrees K2+C6P, K3 0.50 degrees +/- 0.5 degrees 0.5 degrees
Model Caster Cross Caster
K1,2,3 3.00 degrees +/- 1.00 degrees 1.00 degrees
Model Total Toe
K1,2,3 +.24 degrees +/- 0.2 degrees (+.125 in. +/- 0.1 in.)
Steering wheel angle is +/- 5.0 degrees.
The following information should be photocopied and supplied to the customer for future reference.
THIS VEHICLE HAS BEEN EQUIPPED WITH 1990 MODEL TORSION BAR ADJUSTERS
ANY RESETTING OF FRONT END ALIGNMENT OR VEHICLE TRIM HEIGHT (Z-HEIGHT) SHOULD CONFORM TO THE REVISED 1990 SPECIFICATIONS LISTED BELOW.
TRIM HEIGHTS (Z Heights)
Model Z Heilh_@
K1, K2-C6P 157.0 mm +/- 6.0 mm K2+C6P, K3 145.0 mm +/- 6.0 mm
ALIGNMENT SPECIFICATIONS (K 1,2,3)
Model Camber Cross Camber
K1, K2-C6P 0.65 degrees +/- 0.5 degrees 0.5 degrees K2+C6P, K3 0.50 degrees +/- 0.5 degrees 0.5 degrees
Model Caster Cross Caster
K1,2,3 3.00 degrees +/- 1.00 degrees 1.00 degrees
Model Total Toe
K1,2,3 +.24 degrees +/- 0.2 degrees (+.125 in. +/- 0.1 in.)
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
