When to Replace the Universal Joints on your Car
Unless you drive a car or a pickup with rear wheel drive, you should not have to worry about universal joints on your car. Front wheel drive cars have their own shortcomings, but universal joints are not among them. Autos and trucks with rear wheel drive have long drive shafts that extend from the back of the transmission to the rear end on the vehicle.
At the beginning and end of this drive shaft sits a universal joint.
Universal joints are a simple marvel of ingenuity that allow for there to be small differences in the alignment of the transmission and rear end. Essentially, a universal joint is a cross with a cap on each spoke that is filled with roller bearings and grease. Replacing one is not difficult for anyone who has even a small amount of mechanical ability.
Basically, you replace a universal joint whenever it fails.
Failing universal joints tend to manifest themselves in one of three ways. The first way to tell if your universal joint is needing replaced happens when you hear a repetitive groaning sound coming from under your car as you drive. This could be more of a clunking sound if the joint is really bad. Sometimes, before the joint reaches the groaning stage, you will feel excessive vibrating as you drive. It will often be more noticeable at higher speeds, but not always. The third and final way to know if a universal joint is ready for replacement is when your drive shaft falls off the car at one end or the other. Hopefully, you will have diagnosed the issue before this happens.
It can be a good idea to replace a universal joint at other opportunities.
Since universal joints are not a particularly expense part, you may choose to replace this part when having other servicing done. If you have to have the drive shaft removed for any reason, you should consider putting in new universal joints at that time since it will require very little additional labor cost to do so. If your universal joints have been in place for 80,000 or 100,000 miles, you should replace them before taking a trip of any significant length. This will help you to avoid costly repair bills while you are travelling.
You can easily replace the universal joints yourself.
Start by getting an alignment on the universal joint so that the two caps that you want to deal with are nearly horizontal to each other. To achieve this, you may need to move the vehicle backwards or forwards an inch or two to rotate the universal joint. Use needle nose or snap ring pliers to compress the small keeper inside the yoke where the universal joint cap is. Once it is compressed, you should be able to lift it from the yoke and place it somewhere safe. Do the same thing for the other side.
Use a large punch that will still fit inside the yoke opening to drive the universal joint to one side.
This usually requires light tapping more than pounding to accomplish. Once the cap opposite of the one that you are tapping is outside of the yoke, grip the cap and remove it. Since you are replacing the universal joint, you do not have to be especially careful with this cap or the roller bearings inside. The will not be used again. With the cap off and the other cap between the openings of the yoke, you should be able to just incline the universal joint and slide it loose from the yoke. Repeat this process to remove it from the remaining yoke. It is slightly easier if you remove it from the rear end or transmission yoke before removing it from the drive shaft.
Once the old universal joint is removed, it is time to put the replacement one on the car.
Carefully remove each of the caps one at a time and make sure that each one has a sufficient amount of grease inside that surrounds the roller bearings. Most of the time, it is a good idea to add some heavy weight axle grease inside the cap and on the end that the cap covers. Be especially careful to maintain the vertical alignment of the bearings inside the cap. Once each cap has been greased, you should replace it. Usually new universal joints come with a grease fitting that has to be screwed into the universal joint before it is installed on the car. Make sure it is screwed in properly and well tightened.
Remove one cap and insert the universal joint into the yoke on the drive shaft.
This is basically a matter of reversing what you did when you removed the old universal joint. Put the cap on the universal joint and push it into place in the yoke. If it does not slide easily, you will need to make sure that it is aligned correctly and gently tap it into place. It is best to use a punch and a small block of wood. Tap the wood until the joint is flush with the yoke and use the punch to nudge it the rest of the way. Stop tapping on the fitting when the slot for the keeper is visible on the side you are tapping into place. Insert the keepers on both sides.
Now, repeat this process to put the other portion of the universal joint into the yoke.
This is on the transmission or rear end depending on which end of the car you are having to do the repair. When the last two keepers are in place, you can squirt a little grease through the fitting to finish the job. If you do not have a grease gun, remind your mechanic to grease it on your next service appointment. Factory installed universal joints do not always have grease fittings. Consequently, your mechanic may not check if you do not mention it.
