Replace u-joints with ball joints?

[ftwhite3]

I plan to replace my front upper and lower ball joints on my 2004 TJ with 107,000 miles. While I am in there and have everything apart, does it make sense to replace the u-joints even if I can't find a sign of them failing?
Second question is if my right side hub is failing, should I replace left side at the same time since they have the same miles on them?
Last question: I got Moog K series ball joints. I see several people say that Spicer is considered better. Has anyone had bad results from Moog on the TJs?

 

[jazngab]

I plan to replace my front upper and lower ball joints on my 2004 TJ with 107,000 miles. While I am in there and have everything apart, does it make sense to replace the u-joints even if I can't find a sign of them failing?
Second question is if my right side hub is failing, should I replace left side at the same time since they have the same miles on them?
Last question: I got Moog K series ball joints. I see several people say that Spicer is considered better. Has anyone had bad results from Moog on the TJs?

If the U joints were never replaced I say replace them. Mine had no sign of failing but when I replaced them the one u joint was stiff and part of it was dried out. I ended up replacing both hubs too only because I damaged one trying to remove it. Figured I’d keep both same mileage and keep the old good one as a backup. I stuck with spicer ball joints and u joints only based on the overwhelming suggestions from the forum.

 

[Flivver250]

I had to replace one of my ball joints. I did all four. I also got a full differential kit with bearings, and seals. I replaced the u-joints as well. If the seals are old, pulling the axles are likely to cause a leak. While the u-joints passed every test, when I pulled them out, one was rusty puke inside. I also replaced both wheel bearings because I do not intend or want to go back in there for a long time. Do it right the first time. You can always make more money. I never wait for a part to fail. Age is reason enough to give it good maintenance. Any old veterans here who remember Connie Rod?

 

[pagrey]

I was in the same boat at about 100K miles with the u-joints. I bought Moog 370 joints and put them in. They were both toast in less than 10K miles. I now run spicer 5-760x, at least I think that's the part number. I run tiny 31" tires, not exactly hard work on the joints.

My opinion, don't touch a working factory spicer joint, especially if you aren't hard on the axles. If you do replace the joint don't downgrade. I'd just buy a spare spicer and throw it in your trail toolbox.

Edit: same with the hub, if it ain't broke...

 

[Jerry Bransford]

Stick with Spicer ball joints, their quality and longevity is much better than Moog.

This kit... https://www.amazon.com/dp/B00UTD76GY/?tag=wranglerorg-20 The brass inserts shown in the photo aren't used on TJs, they get tossed.

For your axle shaft u-joints, go with the direct replacement Spicer 5-760x which is a stronger and more durable u-joint than the Spicer 5-297x the factory installed. Spicer developed the 5-760x at Jeep's request for the then-new Rubicon, Jeep wanted a stronger u-joint for the Rubicon. https://www.amazon.com/dp/B00QAURWQO/?tag=wranglerorg-20

Might as well replace both unit bearing hubs at the same time, I'd stick with Timken.

 

[jjvw]

It's another hour's worth of work to replace the u joints along with the ball joints. I say it's worth the effort rather than make it a separate job.

If you are feeling really ambitious, the inner axles seals aren't that far away. You'll have a great sense of accomplishment when you wake up the next morning.

 

[makorider]

As to the hub/bearing, if one is going, the other will follow shortly, so do both while you are in there. At least thats been my experience.

 

[TJ Hunnicutt]

When I first read the subject of this thread I was like "how the hell are you going to replace your U-joints with ball joints...and why?".

I third (or fourth) the replace them while you're there idea. I assume that you do not know the complete 107K mile history of the jeep so you don't know when/if they were last replaced. If never (certainly possible), I'd say they were due.

 

[AndyG]

Yep, we require new u joints once the front wheels are torn down if the Jeep has over 50,000 miles, it’s in the forum code book, section 5 (front end/steering section , line 13).

 

[jjvw]

Yep, we require new u joints once the front wheels are torn down if the Jeep has over 50,000 miles, it’s in the forum code book, section 5 (front end/steering section , line 13).

 

[AndyG]

View attachment 80232

I tell you what these guys get called in for a pre gear hearing and I have to sit down in front of Jerry and Chris , Blaine and those guys...they're going to be squirming in their seat when they start getting asked some hard questions about axles, tire size and what their intentions are.

It will be like the movie Sully.

"All right let's go back to the simulator and do Johnson Valley ... You've got 35 seconds"

 

[tworley]

Nothing more to add then whats already been said. You've got everything torn apart, I would go ahead and do both sides (ujoints and balljoints)

 

[Muddyjeep276]

The axle seal on the passenger side especialy is easy to knock out, or make leak when replacing the axle back in.
Ive knocked the seal loose on mine a couple times putting it back in.
Replacing the axle seals is a big job when you cause it by accident like me.