Jeep Enthusiast Forums banner
1 - 3 of 3 Posts

Premium Member
4,665 Posts
Discussion Starter · #1 ·
U-joints are something that our Jeeps for sure need replaced more often than other vehicles. Short driveshafts and extreme angles of the shaft are big contributors, and so it what we do with our Jeeps.

Here is a method that I learned from an old guy about 40 years ago that works really well.
Automotive tire Motor vehicle Wood Automotive wheel system Gas

The first thing I want to establish is where my hammer hits the driveshaft. Also note how the other bearing caps are supported in the vice. It holds the driveshaft up but not to tight to where I cannot pound the shaft downwards. This pic is at the rear diff end so there is no other yoke on this end of the driveshaft. It is the easiest end to replace. If it was the front end there would be a Yoke on the vice rather than just the bearing caps.

If you hit the driveshaft where the hammer is shown in this pic, it will force the upper cap upwards and out of the shaft. Flip the shaft over and repeat to knock the cap on the opposite side out.

Gesture Finger Gas Wrist Wrinkle

Once a joint is removed the next step is cleanup if necessary and start to install the new joint. Most of my install process moves to doing it on the floor of the shop. The concrete floor is the most solid thing in the shop and it is also very level and just eliminates things that workbenches and vices can do that are not in your favor. The floor is the best damn surface to do this on.

This is a lousy pic of what I am doing but I put a cap in the yoke and put my finger into the cap from the bottom and gently tap the cap into the yoke. My finger being inside the cap ensures that no bearings are displaced and knocked out of position when I start the cap. You have to be careful to not press the cap in too far because you still have to get the joint into the yoke.
Bicycle part Nail Automotive tire Gas Wrist

Here I have the cap started and the joint wiggled into place. Notice that I have pulled the joint up into the cap and seated it as far as I can. From here I hit the cap with a hammer to push it in to about flush. I am not an animal, I do not want to destroy or peen the edges of the yoke. It haunts you later.

Automotive tire Fluid Gas Plumbing Auto part

Then I place a socket on the floor under the cap that I have started. I hit downward on the same part of the shaft that I showed in the beginning. It will drive this cap up into the shaft and push the ujoint upward at the same time.
Gas Auto part Metal Electric blue Household hardware

I drive the cap far beyond its final position. Way past where it needs to be to get the clip into it. I want the u joint to extend beyond the other side of the yoke as far as possible . The reason being, I want to be able to drop the other side cap on without misaligning needle bearings and forcing stuff together. This is a really positive way to make sure everything is in line and you are not messing up the needle bearings. I can engage the bearings on both caps positively and not risk damage with a swing of the hammer.
Automotive tire Gas Auto part Nut Metal

Here is an example of how far through I pushed one cap to be able to start the second one. I do pull up on the joint to make it further stick out the other hole but making sure that I do not pull it up to far to disengage the bearing cap that it is already in. If I do this right. I can drop the other cap onto the u joint with my fingers and have the bearings in both caps in line at the same time positively before I touch it with a hammer. This part is where u jont installations most commonly go wrong.
Leg Automotive tire Wood Road surface Gas

an example of how far I knock the first cap through to make sure that I can line up the next cap on the other side. 100% of the time.
Wood Gas Machine tool Engineering Wire

And in the end. Everything is installed and clipped together but your u joint maybe and is most likely a little tight and binds. You put it back in the vice and smack down lightly in the place that I already established that is the only place to hit it with a hammer to seat the caps back against the clips which really frees up the u joint.

My method of where I hit a driveshaft or yoke will only tend to widen it or spread it out but in reality it never does. Using presses and stuff only tends to cave them in and it always seems to.

Hope this helps somebody. The ONLY time it ever fails me is when I am trying to teach somebody. Go figure

11,796 Posts
Nice write up. (y)
Purdy much how I had to do a trail change on the YJ... less having the vice, tho.

side note: I'd like to know how an Az. Jeep can have so much rust on a DL??? :p馃榿

Premium Member
4,665 Posts
Discussion Starter · #3 ·
side note: I'd like to know how an Az. Jeep can have so much rust on a DL??? :p馃榿
That was actually a driveshaft from Michigan XJ that I did at work.

The AZ jeep driveshaft is purdy.
  • Like
Reactions: RockWoRM
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.