The drive axles on front wheel drive vehicles are often called halfshafts. They are flexible shaft assemblies that transmit rotational force from the transaxle to the front wheel assemblies. The halfshaft assembly is made up of an inner and outer Constant-Velocity Joint (CV-Joint) connected to an axle shaft. The inner joint is completely flexible and has the ability of in-and-out movement. The outer joint is also flexible, but cannot move in and out.
Two types of joints are used in the halfshaft, or drive axle. The outboard joint uses what is called a Rzeppa joint design. The shaft end mating with the steering knuckle/hub uses a helical spline to assure a tight, press-type fit. This design provides a no-end play condition between the hub bearing and the driveshaft. With no end play between the hub bearing and driveshaft assembly, the design provides added durability and reduced bearing noise. The inner joint uses what is known as a Tripot design without an over-extension limitation retainer. The left side halfshaft inboard shaft attachment to the transaxle uses a female spline which installs over a stub shaft protruding from the transaxle. The right side halfshaft uses a male spline and interlocks with the transaxle gears using barrel-type snaprings.
The front halfshaft, or drive axle, assemblies use inboard and outboard joint seals made of a thermoplastic material and clamps made of stainless steel. The thermoplastic material performs well against normal handling and operational wear and conditions. However, it is not strong enough to withstand abusive handling or damage due to objects such as sharp tools or the sharp edge of any surrounding component in the vehicle.
The functions of the seal (most often referred to as the CV-joint boot) are to protect the internal parts of the inboard and outboard joint by protecting the grease from extreme temperatures, stones, dirt, water salt, etc., as well as facilitate the movement of the joints.
The clamps are designed to provide a leak-proof connection at the housing and axle shaft for both the inboard and outboard joints.
The CV-joint boots should be inspected regularly and replace immediately if any defect is found. If the boots are damaged, the special grease will run out, become contaminated and water and dirt will get in an quickly wear out the joint. Refer to for CV-boot inspection.
CLICKING NOISE IN TURNS indicates a worn or damaged outer joint, probably due to a cut or damaged boot.
CLUNK WHEN ACCELERATING FROM COAST OR DRIVE also indicates a worn or damaged joint.
SHUDDER OR VIBRATION, especially under acceleration could be from a worn or damaged outer joint or it could be from another source. If the CV-boots are in good condition and there is no obvious damage, look for a tire problem, an engine-related vibration or perhaps a damaged wheel with excessive run-out or out of balance.
VIBRATION AT HIGHWAY SPEEDS could be out of balance rear tires or wheels, out of round tires or wheels or a possible worn outer CV-joint binding or tight.
REMOVAL & INSTALLATION
Because the outer joint is essentially a press-fit in the hub and the steering knuckle also needs to be disconnected from the lower control arm, special tools are needed for this job, including a good-quality hub/spindle puller. Use care is using substitutes or expensive damage may result. In general, halfshaft service is not for the inexperienced or ill-equipped.
- Raise and safely support the vehicle.
- Remove the wheel and tire assembly.
- Disconnect the stabilizer shaft link by removing the through bolt where it passes through the lower control arm and connects to the stabilizer shaft.
- Remove the front halfshaft, or drive axle, spindle nut. The torque specification on this nut is 150 ft. lbs. (205 Nm). To keep the brake rotor and hub assembly from turning when removing the nut, insert a suitably sized drift pin or other suitable tool through the brake caliper inspection opening into the brake rotor's ventilation openings. This should lock the assembly in place so the spindle nut can be loosened. It is good practice to wire-brush any exposed threads on the end of the spindle and apply a generous coating of penetrating oil.
- Detach the tie rod end from the steering knuckle by removing the torque prevailing hex nut. It should be replaced with a new part. This design tie rod has a tapered joint that GM says has been designed to separate easily, unlike previous joints of this type. If required, use a tie rod puller tool to separate the tie rod end from the steering knuckle.
- Separate the ball joint from the steering knuckle by removing the cotter pin and loosening the nut. Do not remove the nut yet. Install a ball joint puller to separate the joint from the knuckle. By keeping the nut in place as the puller is being used to press the ball stud from the knuckle, the threads on the ball stud are protected so the ball joint can be reused. Now remove the puller and the nut and detach the ball joint stud from the steering knuckle.
- Separate the axle from the hub using a hub puller. Don't try to hammer on the end of the spindle or the outer CV-joint and possibly also the hub bearing will be damaged. Use a hub puller to press the spindle out of the hub. It is good practice to leave the hub nut in place to protect the threads on the spindle as the hub puller presses the spindle free of the hub.
Remove the halfshafts (drive axles) from the transaxle, as follows:
- Right Side: GM recommends their axle shaft removing set which consists of C-shaped plates that fit behind the inner CV-joint, between the joint and the transaxle housing. A slide hammer attaches to the C-plates so the halfshaft can be popped free of the transaxle.
- Left Side: Using the subframe for leverage, carefully separate the halfshaft from the transaxle with a suitable prytool in the groove provided on the inner joint.
- Clean all parts well. Inspect the halfshafts and the CV-boots. Service, if required, using the Overhaul procedures found in this section.
- Push the halfshaft into the transaxle. Verify that the halfshaft is seated by grasping the inner joint housing and pulling. It is important to make sure the halfshaft is seated. Do NOT pull on the drive axle shaft, only on the inner CV-joint.
- Install the halfshaft/drive axle end into the hub and bearing assembly.
- Connect the ball joint to the steering knuckle. Tighten the nut to 40 ft. lbs. (55 Nm). Align the slots in the nut to the cotter pin hole in the ball stud by tightening the nut further, if required. DO NOT loosen the nut to align the holes for the cotter pin. Install a new cotter pin.
- Connect the tie rod end to the steering knuckle. Use a new service replacement torque prevailing nut and tighten to 18 ft. lbs. (25 Nm) plus an additional 180° of rotation.
- Install a new service replacement front wheel drive axle nut. To keep the brake rotor and hub assembly from turning when tightening the nut, insert a suitably sized drift pin or other suitable tool through the brake caliper inspection opening into the brake rotor's ventilation openings, locking the assembly in place so the spindle nut can be tightened. Torque the nut to 150 ft. lbs. (205 Nm).
- Install the stabilizer through bolt from the bottom of the control arm to the stabilizer bar link and tighten the nut to 17 ft. lbs. (23 Nm).
- Install the front wheel and tire assemblies. Torque the wheel nuts to 100 ft. lbs. (140 Nm).
- Lower the vehicle.
- Since some transaxle fluid may be lost when the halfshafts are disconnected, check the fluid level. Please see the procedure in this section.
- GM recommends that since the steering tie rod and the ball joint were disturbed, that the front end alignment should be checked and adjusted if necessary.
CV- BOOT REPLACEMENT
Outer CV-Boot Assembly
- Remove the halfshaft from the vehicle, then clamp in a vise. Use soft jaws or wood blocks to protect the finish on the halfshaft.
- Cut and remove the boot retaining clamps with wire cutters.
- Separate the boot from the CV-joint race at the large diameter and slide the boot away from the joint along the axle shaft.
- Wipe the grease from the face of the CV-joint inner race.
- Locate the retaining ring located on the shaft where is passes through the big end of the joint. It may be under a thick layer of CV-joint grease. Spread the ears of the retaining ring with lock ring pliers and remove the outer joint assembly from the halfshaft.
- Slide the CV-joint boot from the axle shaft. If just the boot is being replaced, and the joint is still in good condition (the boot is being replaced before the old one failed), it is possible to reassemble using a new boot and the special grease usually found in a CV-boot kit. Flush the grease from the joint and repack the boot with half of the grease provided with the new boot. If, however, the boot was torn and the joint contaminated with water or dirt, the joint will have to be replaced or overhauled, using the procedures found in this section.
- Install the new boot and clamps (do not tighten yet) on the axle shaft. Make sure the boot is pointing in the correct direction. With the boot in place, install the joint to the drive axle shaft and snap the race retaining ring into place. Put the remainder of the special CV-Joint grease that came in the boot kit, into the joint. Position the new clamp on the boot. The factory uses a special swaging tool for the original installation. Service replacement CV-boot kits normally come with clamps that can be tightened with pliers.
- Remove the halfshaft from the vehicle, then clamp it in a vise. Use soft jaws or wood blocks to protect the finish on the halfshaft.
- Cut and remove the boot retaining clamps with wire cutters. Some technicians may use a grinder to cut the bands, especially the smaller swaged band. Use care not to cut through the boot and damage the sealing surface of the CV-joint housing.
- Separate the boot from the inner CV-joint the large diameter and slide the boot away from the joint along the axle shaft.
- There is a three-arm bearing called a "spider" that is retained on the halfshaft, or axle shaft, by a snapring. Move the CV-joint housing away from the spider to locate the snapring which is in a groove on the end of the drive axle. Spread the ears of the ring and remove the retaining ring along with the spider. Use the same pliers to remove the spacer ring which sits next to the spider on the axle shaft.
- Slide the CV-joint boot from the axle shaft. If just the boot is being replaced, and the joint is still in good condition (the boot is being replaced before the old one failed), it is possible to reassemble using a new boot and the special grease usually found in a Boot Kit. Flush the grease from the joint and repack the boot with half of the grease provided with the new boot. If, however, the boot was torn and the joint contaminated with water or dirt, the joint will have to be replaced or overhauled, using the procedures found in this section.
- Clean all parts well. The spider assembly and the housing must be thoroughly cleaned with a suitable solvent. All traces of old grease and any contaminates must be removed. Dry all parts. Refill the housing with approximately half of the grease from the service kit and provided with the new boot. The other half of the grease goes inside the replacement boot.
- Install the new boot and clamps (do not tighten yet) on the halfshaft. Make sure the boot is pointing in the correct direction. With the boot in place, install the spacer snapring, the spider assembly and the outer retaining ring. Make sure all retaining snaprings are properly seated in their grooves. Position the new clamps on the boot. The factory uses a special swaging tool for the original installation. Service replacement CV-boot kits normally come with clamps that can be tightened with pliers.
Outer CV-Joint Assembly
- Remove the halfshaft and separate the outer CV-joint from the axle shaft following the CV-boot removal and installation procedure. Clean out the grease from the joint to aid in disassembly.
- Use a brass drift to gently tap on the cage until tilted enough to remove the first ball. Remove the other balls in a similar manner.
- Pivot the cage and inner race at 90 degrees to the center line of the outer race with the cage windows aligned with the lands of the outer race. Lift the cage out with the inner race.
- Rotate the inner race up and out of the cage as in Step 2. Clean all parts with solvent and blow dry with compressed air.
- Lightly coat the ball grooves with the provided special CV grease.
- Install the inner race into the cage, cage into the outer race and balls into the cage as removed.
- Refill the joint with half the grease provided.
- Install the joint onto the axle. Make sure the retaining ring is properly seated in its groove.
- Install the boot and clamps using the procedures for Boot Removal and Installation found in this section. Make sure the lip on the rubber boot is in the proper groove in the outer race.
- Install the halfshaft in the vehicle, as outlined earlier in this section.