GM Service Manual Online
For 1990-2009 cars only

Wheel Drive Shafts Description and Operation Front

Front wheel drive axles are flexible assemblies.

Front wheel drive axles consist of the following components:

    • A front wheel drive shaft tri-pot joint (inner joint)
    • A front wheel drive shaft constant velocity joint (outer joint)
    • A front wheel drive shaft
        The front wheel drive shaft connects the front wheel drive shaft tri-pot joint and the front wheel drive shaft constant velocity joint.

The front wheel drive shaft tri-pot joint is completely flexible. The front wheel drive shaft tri-pot joint can move in and out.

The front wheel drive shaft constant velocity joint is flexible, but the front wheel drive shaft constant velocity joint cannot move in and out.

Boots (Seals) And Clamps

The front wheel drive shaft constant velocity joint and the front wheel drive shaft tri-pot joint boots (seals) in the front wheel drive axle are made of a thermoplastic material.

The clamps in front wheel drive axle are made of stainless steel.

The boot (seal) provides the following functions:

    • Protection of the internal parts of the front wheel drive shaft constant velocity joint and the front wheel drive shaft tri-pot joint.
        The boot (seal) protects the grease from the following sources of damage:
       - Harmful atmospheric conditions (such as extreme temperatures or ozone gas)
       - Foreign material (such as dirt or water)
    • Allows angular movement and the axial movement of the front wheel drive shaft tri-pot joint.
    • Allows angular movement of the front wheel drive shaft constant velocity joint.

Important: Protect the boots (seals) from sharp tools and from the sharp edges of the surrounding components.

Any damage to the boots (seals) or the clamps will result in leakage. Leakage will allow water to leak into the front wheel drive shaft tri-pot joint and the front wheel drive shaft constant velocity joints. Leakage will also allow grease to leak out of the front wheel drive shaft tri-pot joints and the front wheel drive shaft constant velocity joints.

Leakage may cause noisy front wheel drive axle operation and eventual failure of the internal components.

The clamps provide a leak proof connection for the front wheel drive shaft tri-pot joint and the front wheel drive shaft constant velocity joint at the following locations:

    • The housing
    • The front wheel drive shaft

The thermoplastic material performs well under normal conditions and normal operation. However, the material is not strong enough to withstand the following conditions:

    • Abusive handling
    • Damage from sharp objects (such as sharp tools or any sharp edges of the surrounding components in the vehicle).

Front Wheel Drive Shaft Tri-pot Joint (Inner Joint)

The front wheel drive shaft tri-pot joint is made with the tri-pot design without an over-extension limitation retainer.

The joint is constructed as follows for vehicles that are equipped with an automatic transmission:

    • The left front wheel drive axle has a female spline. The female spline installs over a stub shaft that protrudes from the transaxle.
    • The right front wheel drive axle has a male spline. The right front wheel drive axle uses barrel type snap rings in order to interlock with the transaxle gears.

Front Wheel Drive Shaft Constant Velocity Joint (Outer Joint)

The front wheel drive shaft constant velocity joint is made with the Rzeppa joint design.

The shaft end (which mates with the knuckle/hub) has a helical spline. The helical spline ensures a tight, press-type fit.

This design prevents end play between the hub bearing and the front wheel drive axle.

Wheel Drive Shafts Description and Operation Rear

The rear wheel drive axles are flexible assemblies.

The rear wheel drive axles consist of the following components:

    • 2 wheel drive inner and outer shaft constant velocity (CV) joints
    • A wheel drive shaft
        The wheel drive shaft connects the wheel drive shaft CV joints.

The wheel drive shaft CV joints are completely flexible. Both wheel drive shaft CV joints cannot move in and out.

Boots And Clamps

The rear wheel drive shaft CV joint boots on the wheel drive axle are made of a thermoplastic material.

The clamps on the rear wheel drive axle boots are made of stainless steel.

The boots provide the following functions:

    • Protection of the internal parts of the wheel drive shaft CV joints.
        The boots protect the grease from the following sources of damage:
       - Harmful atmospheric conditions, such as extreme temperatures or ozone gas
       - Foreign material, such as dirt or water
    • Allows the angular and the axial movement of the rear wheel drive shaft joints.

Note: Protect the boots from sharp tools and from the sharp edges of the surrounding components.

Note: Any damage to the boots or the clamps will result in leakage. Leakage will allow water to leak into the rear wheel drive shaft CV joints. Damage will also allow grease to leak out of the wheel drive shaft CV joints.

Leakage and the loss to grease may cause noisy wheel drive shaft CV operation and eventual failure of the internal components.

The clamps provide a leak proof connection for the wheel drive shaft CV joints at the following locations:

    • The CV housing
    • The wheel drive shaft

The thermoplastic material performs well under normal conditions and normal operation. However, the material is not strong enough to withstand the following conditions:

    • Abusive handling
    • Damage from sharp objects, such as tools or sharp edges of the surrounding vehicle components

Rear Wheel Drive Shaft Constant Velocity Joints

The rear wheel drive shaft constant velocity joint are made with the Rzeppa Design. The shaft end (which mates with the knuckle hub) has a helical spline. The helical spline ensures a tight press-type fit. This design prevents end play between the hub and the front wheel drive shaft.