U-joint help

[Igor Khmyz]

Hey guys, need your help. I am a beginner and am restoring a jeep tj. I and attaching the drive shaft and from what I understand is that the u joint on the front of the drive shaft popped out. Not the entire u joint, but 1 piece. I don't know if I need to replace the u joint, or anything else on the drive shaft. This is my first big project, so I need some help. Thanks

 

[CodaMan]

Make sure are the needle bearing are in place and push it back on and you'll be good.

 

[AndyG]

if it has considerable mileage, you may want to rebuild all 3 joints... You don't won't a double cardan to fail.

If they run quiet and aren't dry, carefully slide it on and reinstall. If it doesn't have fittings, now's the time to add some grease.

 

[qslim]

Completely rebuild all 3 joints..if one is that bad ...they all may be suspect. You don't won't a double cardan to fail.

I don't think he's saying the joint is bad, the cap just popped off.

If the grease is still good & none of the needle bearing popped out, put that sucker back & press on. Not everyone is a nutjob like us that rebuilds everything they touch on their TJs.

 

[TJ4Jim]

I don't think he's saying the joint is bad, the cap just popped off.

If the grease is still good & none of the needle bearing popped out, put that sucker back & press on. Not everyone is a nutjob like us that rebuilds everything they touch on their TJs.

I agree but I just magnified the photo and the stem on the U-joint is trashed, thought it was grease ripples at first.

 

[lBasket]

My U-joints hadn't "failed" completely when I bought my Jeep, but I ended doing all the ones I had in my driveshafts. It reduced highway vibes significantly, so might be worth replacing them if they're old and worn even if they still work.

 

[AndyG]

I agree but I just magnified the photo and the stem on the U-joint is trashed, thought it was grease ripples at first.

Thank you , apologies can be posted now.

 

[mrblaine]

I agree but I just magnified the photo and the stem on the U-joint is trashed, thought it was grease ripples at first.

Bullshit,.

 

[TJ4Jim]

Bullshit,.

Is it grease ripples on the stem ?

 

[mrblaine]

Is it grease ripples on the stem ?

Yes, you can see the circular centerless grinding marks under it. He just had a cap fall off and was not aware that you just push them back on with all the needles in place.

 

[AndyG]

Yes, you can see the circular centerless grinding marks under it. He just had a cap fall off and was not aware that you just push them back on with all the needles in place.

Yep...Needles staying in is a sign of grease ..which is a good thing.

 

[Igor Khmyz]

Thanks guys, I just realized that the cap just popped out. I am not too sure what the needles are, but those are grease lines. I have not driven the jeep yet, since it was damaged when I bought it. I put drive shaft on today and I think I will put in new u joints later, since it is accessible. Thanks again guys, I am still learning.

 

[TJ4Jim]

Thanks guys, I just realized that the cap just popped out. I am not too sure what the needles are, but those are grease lines. I have not driven the jeep yet, since it was damaged when I bought it. I put drive shaft on today and I think I will put in new u joints later, since it is accessible. Thanks again guys, I am still learning.

Needles (bearing) are the rolling part of the U joint cap stacked vertically inside the cap.

 

[Igor Khmyz]

Needles (bearing) are the rolling part of the U joint cap stacked vertically inside the cap.

View attachment 234032

Ok, now that makes sense. That explains why there are grease lines.

 

[qslim]

Thanks guys, I just realized that the cap just popped out. I am not too sure what the needles are, but those are grease lines. I have not driven the jeep yet, since it was damaged when I bought it. I put drive shaft on today and I think I will put in new u joints later, since it is accessible. Thanks again guys, I am still learning.

You're in the right place to learn!

 

[FishinSam]

Thanks guys, I just realized that the cap just popped out. I am not too sure what the needles are, but those are grease lines. I have not driven the jeep yet, since it was damaged when I bought it. I put drive shaft on today and I think I will put in new u joints later, since it is accessible. Thanks again guys, I am still learning.

Replace them while you have the shaft out. Cheap insurance against having to pull the driveshaft and do them later... I learned this the hard way. Changed the pinion seals and, SURPRISE!, ujoints started to go 3 months later. Mine were old but seemed solid at the time... I was stupid and in a hurry to go wheeling. Don't be a me.

 

[bucky]

May I suggest a little Utube watching. Several good ujoint posts there.

 

[Rubicon88]

As long as you don't have needle bearings rolling across the garage floor and lost a couple it can be reused.
Just neatly line them up vertically but make sure you aren't missing one!!!!

That said if the u joint replacement date is unknown or original...since the DS is off now is a great time to replace them.

 

[Blackjack]

Joint looks ok other than it is out of grease. The cavity in the trunnion is empty. You can carefully take the joint apart and fill those cavities back up and reassemble the joint.