GM Service Manual Online
For 1990-2009 cars only

The following components are supported by a front crossmember frame which is rigidly bolted to the body rail at 6 locations.

    • The engine
    • The front suspension components
    • The steering linkage

The following components are supported by the rear suspension frame which is attached to the body rail through rubber insulators at 4 locations:

    • The rear drive axle assembly
    • The rear suspension components

The transmission support is rigidly bolted to the floor pan and supports the transmission extension.

The underbody frames must be properly aligned to maintain the correct transmission, suspension and wheel alignment.

Important:  In the event there is evidence of structural damage to the frames they must be replaced.

The individual underbody components contribute directly to the overall strength of the unibody. Use proper metal panel bonding techniques during service repair operations to the underbody. Refer to Metal Panel Bonding in Collision Repair for metal panel bonding information and for vehicle preparation.

The components must be corrosion protected whenever body repair operations damage or destroy the original sealing surfaces. Use a two part catalysed primer when corrosion protection is needed to welded surfaces. Apply the sealers and anti-corrosion materials as necessary. Refer to Anti-Corrosion Treatment and Repair. Do not combine paint systems. Refer to Basecoat/Clearcoat Paint Systems, for further information.