How to Change a Universal Joint on a Chevy Blazerby K.K. Lowell
Changing a driveshaft universal joint in a Chevy Blazer is a job that a person handy with tools can do quite easily. There are no special tools required, although a universal joint press is strongly recommended and can be rented at many automotive parts stores.
Using a floor jack, raise the Blazer high enough to allow easy access to the driveshaft. Securely support the vehicle on jack stands before crawling under it.
Remove the four 11mm bolts holding the rear yoke of the driveshaft to the differential.
Place the pry bar between the universal joint and the differential yoke. Pry the driveshaft out of the differential yoke if it does not easily come out.
Pull the driveshaft toward the rear of the vehicle to take it out of the transmission.
Melt the nylon locks out of the joint if you are replacing an original equipment universal joint. Any joint that has been previously replaced will have lock rings installed so this step is not necessary. These nylon locks are located in the ears of the yoke, just behind the area where the bearing caps are pressed in. They are visible as small white plastic dots, one on each side of the ear.
Clamp the universal joint in the universal joint press and push it out of the yoke. The press pushes the cap out when you turn the driving screw in a clockwise direction. Be sure to line up the end of the press which has the hole to allow the bearing cap to enter it without obstruction.
Remove the bearing cap on the side of the joint which was pressed out of the yoke. The bearing cap simply pulls off the joint post. Turn the the universal joint press over and push the joint out of the other side of the yoke.
Remove the second bearing cap when it is exposed. Next, remove the tool from the driveshaft and take the universal joint out of the middle of the yoke.
Take the bearing caps off one cross of the new universal joint. Being very careful to avoid contacting the yoke with the universal joint, place one of the capless posts of the joint through the yoke to the outside. Put the bearing cap back on.
Using the universal joint tool, press the bearing cap back into the yoke. Push it far enough through to allow you to install the bearing cap back on the opposing post.
Install a lock ring on the bearing cap you pushed through the yoke. The locks snap into the groove on the inner end of the bearing cap.
Press the joint into the yoke until the lock contacts the inside of the opposing ear and you can install the lock on the second bearing cap.
Install the supplied grease fitting in the joint. Some replacement joints do not have a grease fitting, so this step may not be necessary.
Slide the driveshaft back into the transmission.
Insert the rear of the driveshaft into the differential yoke. Be certain to center the bearing caps in the yoke. This should be a fairly tight fit. You will likely need to turn the differential yoke by hand until the yoke and the driveshaft line up properly.
Use a drop of threadlocker, such as Locktite 242, on each of the 11mm bolts. Thread the bolts into the differential yoke and tighten uniformly.
Recheck that the bearing caps are centered in the differential yoke.
Remove the jack stands and test drive the vehicle.
- Never go under a vehicle which is not supported by jack stands. Jacks have been known to fail, causing the vehicle to crush people to their death. Place the vehicle on the jack stands and, from outside the vehicle, attempt to shake it off the stands. Go under the vehicle only after you are certain it is rock steady.