OEM tech 101, replacing a u-joint

I had to swap in a new front driveshaft today, so here's some basic tech for anyone who’s never changed a U-joint. There’s a couple different ways of accomplishing it, and here’s one way…with a ball joint press kit (about $40). I bought it last year because I’m eventually going to change ball joints and axle end control arm bushings, but it works great for UJ’s too. I clamp it in a bench vise also.

Press kit:



start by removing the clips that hold the bearing caps in place, using a pair of needle-nose pliers:



after both clips are removed, mount the joint inside the press:



press the joint thru the yoke, almost the whole way across, to push the opposite side cap out so you can remove it



pull the bearing cap off, put the UJ back in the press in the other direction, and reverse the process to push the other cap out of the yoke



one it’s pressed the other direction, pull that cap off and remove the joint



to install the new UJ, make sure the zerk fitting is facing the direction of the shaft (if it is greasable). Remove the zerk now, so you can press the joint in fully. You’ll reinstall it later



remove two bearing caps from opposite sides of the new UJ, put one cap squarely in the yoke and slip the cross inside



press the bearing cap thru the yoke until it is pressed ¾ of the way through, and line up the cross

check the needle bearings on the other cap to make sure they are all seated and none have fallen out of place, then install the cap inside the opposite side





flip the yoke over in the press and press that cap inside the yoke until the joint is centered. If it gets hard to press, stop and loosen the press and check the needle bearing to make sure they are all still in place



when it’s centered, install one of the clips in the yoke



flip the yoke over and install the other clip on the opposite side. You might have to move the joint slightly from side to side in order to get both clips to seat inside the grooves. Make sure each clip is seated fully inside the grooves on both sides



rotate the joint from side to side to ensure it moves freely. If it’s tight, tap the yoke shoulders all around with a hammer while rotating the joint to unload the pressure on the needle bearings. You can literally feel them loosening up



reinstall the zerk, if applicable



finished install, go drink a beer…..



reinstall the driveshaft, and yer done!

nice write up

nice pictures. mine never come apart that easy
Anyone ever tried one of these I bought one but havent used it yet

I see that at the pinion, your u joint zerk in on the side facing foward.
Where do you place the zerk fittings on the u joints in double cardan?
Both on the rear side and on oppostie sides from one another, for balance?

OLAK said:

nice pictures. mine never come apart that easy
Anyone ever tried one of these I bought one but havent used it yet

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Thats some expensive chit man....


Hey jeff, is that a harbor freight kit ?

That looks like the HF kit I bent doing ball joints on one of my 89's.

May I have your permission to .pdf and post on WiP? That's the sort of thing I've been collecting, and I finally got enough to get the page started. This saves me having to do one more writeup...

mage said:

I see that at the pinion, your u joint zerk in on the side facing foward.
Where do you place the zerk fittings on the u joints in double cardan?
Both on the rear side and on oppostie sides from one another, for balance?

Click to expand...

Non-servicable joints in the DC, so I really don't know. I doubt you'd be able to get a grease fitting, standard/needle or otherwise, up in there to actually get grease into them anyway (without dropping the shaft).

Rich.....yeah, HF press (mounted in a HF vise, too) Picked it up on sale for $30. Works great for U-joints.....but I snapped it in half two weekends ago trying to press out axle end UCA bushings:laugh3: Took it back and exchanged it, and eveyone asked WTH I was doing with it.

Jeff

edit: no problem Jon....go for it. Like I said, it works great for UJ's, but YMMV on "other" stuff.....

Thank you. May I have your proper name and email address, so I can credit your correctly?

Here's the page where it's going to end up - http://www.geocities.com/JeepI6Power/writeups.html. I'm usually looking for more, now that I've finally got it started...

Thanks i subscribed to this.

Jeff in VA said:

Non-servicable joints in the DC, so I really don't know. I doubt you'd be able to get a grease fitting, standard/needle or otherwise, up in there to actually get grease into them anyway (without dropping the shaft).

Click to expand...

OEM DC joints are usually not greasable. Aftermarket "greasable" joints are available, but they will have a "cup zerk" in one of the caps, vice the regular "nipple zerk" in the cross. I've seen them. You'd need a special adapter for them - but at least the zerk would be somewhere you can reach.

when I picked up my ujoints last year from NAPA, they came with both the standard nipple fitting and the inverted fitting. You just need a needle attachment for your grease gun (around $10 at NAPA, I think).

Excellent write up with actual clear daylight pictures!

Question for anyone that knows about this. I'm doing the rear driveshaft for my 99, I have all three of the joints pressed completely one way but I can't get either bearing cap off any of them. I've tried busting the rust loose around them with a hammer, I've used PB Blaster, etc. I'm confused if you're supposed to take the cap off that gets pushed out of the "U" itself first or if it's the one that gets pushed to the inside of the "U" first. If anyone understands my description and knows the answer please let me know.

pull the cap that's sticking out of the yoke (see the fourth picture), then press the joint in the opposite direction to push the other cap out of the yoke, and take it out. For the first cap, you may have to use channel locks, or you could clamp the cap in a vise and see-saw the driveshaft back and forth to get it out.

Check also to see if the zerk fitting is preventing the joint from being fully pressed to one size. If it is, remove it and you can get an extra 1/8" or so of movement.

HTH,
Jeff

Jeff in VA said:

pull the cap that's sticking out of the yoke (see the fourth picture), then press the joint in the opposite direction to push the other cap out of the yoke, and take it out. For the first cap, you may have to use channel locks, or you could clamp the cap in a vise and see-saw the driveshaft back and forth to get it out.

Check also to see if the zerk fitting is preventing the joint from being fully pressed to one size. If it is, remove it and you can get an extra 1/8" or so of movement.

HTH,
Jeff

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Jeff,
Thanks for the quick response. I have used channel locks for about 5 minutes and they just keep slipping; I guess vice grips may be in order. For being a 99, this shaft is rusty as a somgun. Oh it doesn't have zerks since it still has stock U-Joints, but now that I know the order...I will get it out somehow.
Thanks again for the awesome write up!
-Collin

Yup - use vice-grips on the cap once you've got it pushed through. I have had luck removing very stubborn caps by pushing the joint back through to the other side. I don't know if that relieves tension or whether the other cap was just looser...

Jim www.yuccaman.com

Yucca-Man said:

Yup - use vice-grips on the cap once you've got it pushed through. I have had luck removing very stubborn caps by pushing the joint back through to the other side. I don't know if that relieves tension or whether the other cap was just looser...

Jim www.yuccaman.com

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Yeah, used vice grips and spun them right off, it was a success! Thanks fellas!

90PioSport99 said:

Jeff,
Thanks for the quick response. I have used channel locks for about 5 minutes and they just keep slipping;
-Collin

Click to expand...

According to the Jeep manual:
Grasp the protruding bearing by vise jaws. Tap
the link yoke with a mallet and drift to dislodge the
bearing cap from the yoke.

I have used the bench vice with excellent results.