Inspecting And Replacing CV Joints

Words and Photos By: Mark Yanochko

Constant Velocity (CV) joints transmit power from the transaxle to the drive wheels under all operating conditions and a wide range of driveshaft angles. These components are protected from the elements by flexible boots, usually made from neoprene or similar material. If these boots are damaged, water, dirt and grit can contaminate the lubricating grease, causing premature wear.

Inspecting these CV joints is rather straightforward. In this article we’ll review these inspection procedures, along with some checks for long-term wear. In addition, we’ll talk about CV joint replacement.

The inner and outer CV joints, along with the driveshaft that connects the two, is known as a halfshaft assembly (Figure 1). The outboard joint, A, is a Rzeppa-style joint which only allows for a change in the driveshaft angle. The inboard joint, B, is a tripod-design which allows for both changes in driveshaft angle and length. This joint has a much larger body than the outboard joint.

Vehicle noise and vibration will probably prompt you to check the CV joints. Inboard joints that are bad usually cause vibration at different speed ranges. Outboard joints can cause clicking noises. To check the outboard joint, turn the wheel full lock and drive the car in reverse, as shown in Figure 2. When driving in reverse, the wheel on the outside of the circle, C, will click if it is bad.

Now let’s get back under the car. If the CV joints are good, you should be able to grab the halfshaft, D (Figure 3), and move it back and forth. If not, an engine mount might be bad, causing the engine to sag. If the mounts are okay, the inner joint is bad.

The boots that protect the CV joints are essential to the life of the joint. Besides holding the grease inside the joint, it also keeps the elements out. Pull back the boot, E, to expose the valleys and look for cracks and splits in the material as shown in Figure 4. If the boot is damaged, replace it or the whole joint. Repeat this procedure on all the CV joints.

If you determine that one of the CV joints is bad and requires replacement, the entire halfshaft must be removed. In most cases, it’s just easier to install a new halfshaft assembly than try to replace a damaged boot or joint. Special tools are required and a lot of time is involved. Let’s review these procedures.

To remove the halfshaft, first remove the cotter pin, nut lock and hub retaining nut, F, on the outer end (Figure 5). To access the nut, remove the cotter pin and nut lock. After the nut lock is removed, you’ll see a wave spring, G, that must be saved and re-used (Figure 6). This spring maintains pressure on the cotter pin. Now you can remove the nut.

It should be noted that if you have an impact wrench, the wheel can be removed from the vehicle. If an impact wrench is not available, the wheel must remain on the ground while a breaker bar is used to loosen this hub retaining nut. Remove the wheel cover, or the center cap on cast wheels, to access this nut. After the nut is removed, there is a spacer, H, that must be saved and re-used (Figure 7).

If the wheel was on the ground to remove the nut, lift the vehicle and remove the wheel. Next, remove the brake caliper, rotor and the lower ball joint (on the minivans, you’ll have to remove the strut from the knuckle to access the lower ball joint). Pull the steering knuckle away from the stub end of the halfshaft to remove the outer CV joint from the knuckle.

With the halfshaft supported, remove the inner CV joint from the transaxle housing. This is done by placing the end of a pry bar, J, between the transaxle case, K, and the CV joint housing, L (Figure 8). This action will disengage the snap ring from the transaxle side gear.

To install a new halfshaft, perform the removal procedures in reverse order. Start by inserting the inner CV joint into the transaxle case. Push on the inner joint until the snap ring engages. The snap ring is properly engaged if you cannot remove the joint by hand. Also, remember to tighten the nut on the outer joint to the correct torque spec. And, if the nut has a nylon insert, replace the nut with a new one.

For a complete listing of Mopar CV axle assemblies—including reman assemblies—contact your Mopar Magazine dealer.