Front axle u-joints question

Reidminer

Reidminer

TJ Enthusiast
Joined
Jan 9, 2019
Messages
376
Location
Syracuse NY
Hi all!
So I’ve been updating my list of things to work on on my Jeep to get it as trail capable as it can be(within my budget) as well as just generally reliable as it’s my DD as well.
Anyway, I noticed when I was under my rig the other day that my front axle u-joints seem to be pretty rusted. There also seems to be some play in that area as well. Upon having my dad take a look(a bit more mechanic savvy than I) and he thinks that while the u-joints could/should definitely be replaced soon, that the movement isn’t caused by that, but by some other issue.
I’ll include a pic and video I took earlier so y’all can see what I’m talking about.

So my questions are, 1)what is causing the movement I see, that I’m pretty sure shouldn’t be there? 2)would I be better off just eating the cost and upgrade my axle shafts now rather than later? And is that something I can do one axle at a time? 3)is my dad wrong and this is just an issue caused by the u-joint that is a relatively simpler and cheaper fix than new axle shafts?

I fully planned on upgrading axle shafts at some point down the road but hoped I could wait till I bought new tires as that is gonna happen sooner. I should mention, it’s a 2000 TJ sport with transplanted Dana 44’s and 4.88’s and running 37’s. Now I know I should be running something like RCV’s if I’m gonna have 37’s, but it’s how I bought the rig(and again I plan to upgrade but wanted to wait a bit). Like I said it’s my DD and I don’t have to wheel it(if this movement issue is indicative of something that would break if I pushed it on the trails), but I would like to just get some more info on what’s up and go from there. So any help is appreciated! Video below

5B9373B3-9A07-4926-94AE-7F72C1A0C936.jpeg
 
There is surface rust, but I’d think that’s normal for your area?

Do they make any noise? Are they sealed or greasable?
 
RMETeeJay said:
There is surface rust, but I’d think that’s normal for your area?

Do they make any noise? Are they sealed or greasable?
Click to expand...
I linked the video, did that work for you?
Interesting okay. Well I bought it in NC in January so it hasn’t been in NY long lol.
and no, no noise that I can hear, and as far as I can tell they are not greasable
 
Your video link says "request access". You should be able to post a smallish video directly.
 
Reidminer said:
I linked the video, did that work for you?
Interesting okay. Well I bought it in NC in January so it hasn’t been in NY long lol.
and no, no noise that I can hear, and as far as I can tell they are not greasable
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Yes, works now.

What are your goals for it? What kinds of wheeling do you want to do? 37s really require some advanced modifications to work correctly.

Complete your profile with all of your Jeep’s details (it’s helpful to know what your particular setup is).
 
RMETeeJay said:
Yes, works now.

What are your goals for it? What kinds of wheeling do you want to do? 37s really require some advanced modifications to work correctly.

Complete your profile with all of your Jeep’s details (it’s helpful to know what your particular setup is).
Click to expand...
Oh, didn’t know I could do that! I definitely will.

I know 37’s takes a lot to pull off correctly, but I got pretty lucky with this one as it is a decent ways along in terms of mods.

As far as what are my goals for this Jeep, well my rough timeline is in the next 3-4 years it’ll become more of a dedicated trail rig as I’ll get another vehicle by then. Once that happens, as long as I have the money, I’ll be upgrading it. Lofty goals are stretch and tons. Again, long term goal is moving out of NY, to the west coast as I prefer crawling and rocks and more technical riding rather than the limited options I have in the northeast, and I don’t like mud bogs or deep water type stuff.

I know this is long winded but in the next year or two, while I’m still DD’ing it and living in NY, I want to have no worries driving it to work every day, and be able to take it to the few places within a couple hours drive from me(BHM, Rausch creek, and like one more) and to wheel it with as much confidence in the build as possible. So why would that look like budget wise for me optimally? Fixing whatever this issue is, getting my rear air locker to work(I believe there’s a leak) and full skid plates. Everything else on this Jeep is in great condition and doesn’t need attention(engine, suspension, body, frame, interior, top). Does that help?

alright now I’m gonna fill out my profile I guess haha
 
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Reidminer said:
Oh, didn’t know I could do that! I definitely will.

I know 37’s takes a lot to pull off correctly, but I got pretty lucky with this one as it is a decent ways along in terms of mods.

As far as what are my goals for this Jeep, well my rough timeline is in the next 3-4 years it’ll become more of a dedicated trail rig as I’ll get another vehicle by then. Once that happens, as long as I have the money, I’ll be upgrading it. Lofty goals are stretch and tons. Again, long term goal is moving out of NY, to the west coast as I prefer crawling and rocks and more technical riding rather than the limited options I have in the northeast, and I don’t like mud bogs or deep water type stuff.

I know this is long winded but in the next year or two, while I’m still DD’ing it and living in NY, I want to have no worries driving it to work every day, and be able to take it to the few places within a couple hours drive from me(BHM, Rausch creek, and like one more) and to wheel it with as much confidence in the build as possible. So what would that look like budget wise for me optimally? Fixing whatever this issue is, getting my rear air locker to work(I believe there’s a leak) and full skid plates. Everything else on this Jeep is in great condition and doesn’t need attention(engine, suspension, body, frame, interior, top), obviously there are larger things that could use an upgrade to deal with 37’s but tryna keep the budget small till I move lol. Does that help?

alright now I’m gonna fill out my profile I guess haha
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There are other folks here who will be better able to provide input for that level build. I honestly don’t know what is needed joint and axle wise for 37s. If you’re not sure what mods you have, post some snaps of them.

Back to your original question about the U Joint, I think that’s normal play from the diff backlash.

I would recommend spending some time removing rust and treating it, especially if you plan to run it winters.

Most of all, get out and wheel it!
 
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RMETeeJay said:
There are other folks here who will be better able to provide input for that level build. I honestly don’t know what is needed joint and axle wise for 37s. If you’re not sure what mods you have, post some snaps of them.

Back to your original question about the U Joint, I think that’s normal play from the diff backlash.

I would recommend spending some time removing rust and treating it, especially if you plan to run it winters.

Most of all, get out and wheel it!
Click to expand...
Ah well I appreciate the input nonetheless! Yeah I’ll have to post pics of my axle soon as I’m still unsure what brand my front Dana 44 is lol.

Yeah tomorrow actually I’ll do some cleaning on those u-joints and see how they look. And good to know on the movement.
Yeah unfortunately, until I move west(1-2 years from now) my Jeep and I will have to suffer through winters lol.
 
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Reidminer said:
Ah well I appreciate the input nonetheless! Yeah I’ll have to post pics of my axle soon as I’m still unsure what brand my front Dana 44 is lol.

Yeah tomorrow actually I’ll do some cleaning on those u-joints and see how they look. And good to know on the movement.
Yeah unfortunately, until I move west(1-2 years from now) my Jeep and I will have to suffer through winters lol.
Click to expand...
U-joints don't care one bit about rust on the outside.
The grease on the inside and the needle bearing condition is everything....all of which you can't tell anything from outside.

Two things...
#1 You've got back lash...
Normal!!!
#2 your camera is shaking with your movement. It's hard to tell anything with the camera bouncing.
Possibly****
At the very end i think i spot a lateral slop movement...but again it's hard to tell with the camera bounce.

If you're unsure replace the u-joints with some spicer.
Especially not knowing the age you can start at ground zero.

Just know this...if you're doing that you have to remove the wheel bearings/hubs to pull the axles. If the WB's are in question as well... now is the time to replace those too.

Good luck
 
Rubicon88 said:
U-joints don't care one bit about rust on the outside.
The grease on the inside and the needle bearing condition is everything....all of which you can't tell anything from outside.

Two things...
#1 You've got back lash...
Normal!!!
#2 your camera is shaking with your movement. It's hard to tell anything with the camera bouncing.
Possibly****
At the very end i think i spot a lateral slop movement...but again it's hard to tell with the camera bounce.

If you're unsure replace the u-joints with some spicer.
Especially not knowing the age you can start at ground zero.

Just know this...if you're doing that you have to remove the wheel bearings/hubs to pull the axles. If the WB's are in question as well... now is the time to replace those too.

Good luck
Click to expand...
Thanks for the reply! Yeah I guess you’re right about the u-joints, as long as the interiors are fine. What do you mean by, I’ve got ‘backlash’ and that it’s normal? Oops yeah I was trying to film a video quickly. I took another one today so I’ll throw the link below. It’s less shaky and I tried moving it in different directions for a better understanding.

And yeah that’s what I was talking over with my dad, it seems there’s a good amount of disassembling involved in replacing the front u-joints so I’ll have to plan a full day for that probably. Wheel bearings and hubs are newer(receipts from PO show they were upgraded about 2-3 years ago and don’t show signs of needing replacing https://drive.google.com/file/d/1-hwejCwTapJwI_udsvVnuOTaz9f5fmYn/view?usp=drivesdk
 
Are you planning on upgrading the shafts as well? If so while you are under there with everything apart now would be the time. Same with ball joints.
 
Claybirdd said:
Are you planning on upgrading the shafts as well? If so while you are under there with everything apart now would be the time. Same with ball joints.
Click to expand...
So, I mean yes I do plan to upgrade to RCV’s, I was just hoping I could wait until I moved west(2 years max from now) just because that’ll be about $1500-2k when I do go to do that. And I’m going to need new tires sometime this year and that’ll also be about $1400 so that’s why I’m wanting to wait if possible on the shafts. So if the movement I see isn’t anything to worry about and either leaving it alone for the time being or just upgrading the u-joints is a good decision, then I’m fine with that.
 
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Backlash is the "slop" your seeing being able to move the axle shaft back and forth. It's the gears in the diff meshing between forward and reverse
 
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Reidminer said:
So, I mean yes I do plan to upgrade to RCV’s, I was just hoping I could wait until I moved west(2 years max from now) just because that’ll be about $1500-2k when I do go to do that. And I’m going to need new tires sometime this year and that’ll also be about $1400 so that’s why I’m wanting to wait if possible on the shafts. So if the movement I see isn’t anything to worry about and either leaving it alone for the time being or just upgrading the u-joints is a good decision, then I’m fine with that.
Click to expand...
Not everyone here is a fan of the RCVs, I certainly am not. I'd stick with conventional 4340 axle shafts with u-joints. Their claim of eliminating vibrations caused by the u-joints is a cure in search of a non-existent issue. They're expensive and their big size often causes interference here and there. I upgraded to 4340 27 spline front shafts in my previous TJ and I'm running 4340 30 spline front shafts in my current TJ... both with conventional u-joints and never a problem with either of them.
 
Jerry Bransford said:
Not everyone here is a fan of the RCVs, I certainly am not. I'd stick with conventional 4340 axle shafts with u-joints. Their claim of eliminating vibrations caused by the u-joints is a cure in search of a non-existent issue. They're expensive and their big size often causes interference here and there. I upgraded to 4340 27 spline front shafts in my previous TJ and I'm running 4340 30 spline front shafts in my current TJ... both with conventional u-joints and never a problem with either of them.
Click to expand...
Well I’m certainly all ears for other options, especially if it’s cheaper yet still high quality! Is there a specific brand I should look for if I go the route you detail?
 
I went with yukon brand 4340 27 spline shafts and spicer 5-760x joints. Bombproof for the type of wheeling I do on 35x12.5x15's.
 
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