Questions and Answers

GMC U-Joints Q. Is there a site that you know of that tells me (in extreme dummy terms) how to replace a u-joint? 1993 GMC Sierra Extended Cab full size 4x4. It's the rear one (don't even know if there's a front one ;-)

I know it's the U-joint cause my mechanic Hubby told me, but he's been sick lately and I can't afford to hire someone to do it. If they can do it, so can I but need a bit of help. Any ideas?

Thanks,
Terrye

A. I like your attitude Terrye. Just because you're a Lady doesn't mean you can't do what a man can do.

Replacing a U-joint does take a certain amount of skill however. To do it you'll need a fairly heavy vise, a BFH (ask your Hubby what that stands for) and a narrow punch. To take out the drive shaft remove the four screws holding the two U-clamps holding the rear U-joint to the pinion flange. Mark the drive shaft and the flange so you can replace it in the same orientation when you're done. Remove the two exposed bearing caps. If you look inside of the bearing caps on the drive shaft you'll see a snap ring. Use the punch and hammer to knock out the snap rings on both caps. It'll fight you but they will come out. Don't worry about breaking them, you got new ones with the new joint.

Once the snap rings are out, support the U-joint on the jaws of the vice. Now get your BFH and hit the drive shaft right where the yoke is welded to the drive shaft. This will drive the bearing cap out of the yoke. You'll have to hit it fairly hard and it will take a couple of shots to get it out. Once it's out, turn the drive shaft over and drive out the other cap in the same way.

Now that the old joint it out, use some sandpaper or emory cloth to clean and smooth the yoke where the bearing caps sit. You can put some oil or grease in there to help the new caps slide in.

Okay, here's where it gets tricky. Inside the new cap is a bunch of small needle rollers. It is VERY important that you don't drop or lose any when you put the caps in. Carefully take the four bearing caps off the new joint and place them someplace where they won't get knocked around. Take the joint and place it inside the yoke. Take one cap and slip it in the yoke and slide the joint into it. Lightly tap the cap so it starts to slide into the yoke using the joint to keep the rollers in place. Once it's fairly well started, place the second cap in the yoke. Put it into the vive and close the vice so it presses the caps in. When they move in close enough, slide the joint so it is in both caps enough to hold the rollers. Tighten the vise until the caps are flush with the yoke.

Now the joint is holding the rollers so you don't have to worry about them falling out. Use the hammer and punch to drive one cap in and pop the new snap ring in. Then turn it over and do the same on the other side. Now it's ready to go back in the truck. Put the last two caps on, line up the marks you made and reinstall the two U-clamps and tighten the nuts. That's it, you're done.

I hope this explains it enough for you to do it. If anything is unclear you can call me and I can go over it with you again. Please, let me know how you make out.

Additional Information provided courtesy of ALLDATA