GM Service Manual Online
For 1990-2009 cars only

Rear axle wind-up may cause launch shudder even when all of the working angles are within specifications. Rear axle wind-up occurs when heavy torque during acceleration causes the pinion nose to point upward. Inspect the following components for breakage, wear, or deterioration which may allow the axle to move enough to cause launch shudder:

    • Transmission mount replacement. Refer to Transmission Mount Replacement in Manual Transmission -- Medium Duty.
    • Transmission support replacement. Refer to Transmission Support Replacement in Manual Transmission -- Medium Duty.
    • Transmission mount replacement. Refer to Transmission Mount Replacement in Manual Transmission -- Medium Duty-Allison.
    • Leaf springs. Refer to Leaf Spring Replacement in Rear Suspension.
    • Spring bushings. Refer to Leaf Spring Replacement in Rear Suspension.
    • Tandem axle torque rods. Refer to Torque Rod Replacement in Rear Suspension.
    • Tandem axle equalizing beams. Refer to Equalizing Beam Replacement in Rear Suspension.
    • Tandem axle equalizing beam end bushings. Refer to Equalizing Beam Replacement in Rear Suspension.
    • Tandem axle equalizing beam center bushings. Refer to Equalizing Beam Replacement in Rear Suspension.