Should I replace my unit bearings?


WallyWest

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Have 150k miles, been replacing suspension parts. Still has a feeling of looseness in general, hard to describe, just a lot of wiggles, jitters, etc... Some of that is to be expected with a TJ I know, but it's excessive even still.

So anyway, at that mileage would you just replace them on general principles? Or should the OEM bearings last a lot longer than that? Based on the overall condition of the frame, skids, etc... I would feel pretty confident that it wasn't abused or anything, so I'd assume just normal wear and tear.

I'm not looking to make it ride like a Cadillac, just taming the worst of it's bad habits.

Oh, and what brand is preferred if I do replace them?
 

Jerry Bransford

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Timken is the brand to go with. With the front tires off the ground do feel any movement/slop when you wiggle the tires around that could be attributed to the hubs?
 

Rubicon88

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These sealed hub/bearing combo will let you know when it's time. Sure you can do the move test but honestly when they start to go south you'll get a growl. Driving in an S pattern will make it growl then go away pending if you've got weight on it then take the weight away. (Body lean)

Wiggles. Jitters...

Tell more of your jeep. Lift? Tires and condition...
Shocks abd age. Steering stabilizer and age.
Ball joints?

Get someone to steer it a few inches back and forth (enginr not running) while you watch every steering joints.
 
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WallyWest

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No growling yet, I've had that on a truck I owned years ago and from what I remember it wasn't subtle. I can't feel any excessive play with the wheel off the ground. But I would be interested in any good way to test the ball joints. From what I've read there is some vertical movement to be expected on the TJ.

Tie rod ends were replaced a year or so ago, by the place I bought it from. Steering otherwise seems ok. I have aligned it since lift was installed. No sloppy steering, it responds to small input while going straight.

This thread details my suspension components and one of the issues I've been trying to diagnose. Except one thing I didn't mention in that thread is a new Currie track bar in front. Both axles now centered.

Tires are 30x9.5 General Grabber ATx, with only 5k miles or so on them. Balance is suspect, I need to have that checked.

 

bromel

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My passenger-side unit bearing was toast, but I could barely hear the growl. It was only at 50mph I could hear a very slight hum, which came and went with increased speed. They're not that expensive, so I'd just change them.
 
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WallyWest

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Oh, and also a TC drop, about 3/4 inch.

All of the stuff I've replaced has helped tighten the handling up, but hasn't eliminated the problems entirely.
 

Quigley

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I think it depends on if you want to tackle it now and whether or not you do the work or you have a shop do it. With 150k I'm sure everything is about due for a replacement. I went to replace my rotors and brakes and was checking the u-joints and unit bearings for play when I decided to just go a head and replace the u-joints, unit bearings, and ball joints. My jeep had about 130,000 miles at the time. Jack up the wheel and grab the tire from the 9 and 3 o'clock position and shake it. If it's loose it's usually tie rods... grab the wheel from the 12 and 6 o'clock position and shake and it's usually ball joints that allow wiggle. Spin the wheel and listen for metallic grinding sounds. Could be brakes if you hear it towards you or unit bearings if it's sounds further in. You can also run your hand across the rotor and feel for irregularities bumps and rough spots. Only really special tools needed are a 36mm socket, big C clamp to compress the calipers if needed. A 4wd ball joint kit. I bought mine from harbor freight from under $40, Jack and jack stands. 3/8 drive sockets, and breaker bar or use an impact wrench save yourself lots of time. Just guesstimating but having a shop do all that would be probably well over a grand.
 

Rubicon88

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No growling yet, I've had that on a truck I owned years ago and from what I remember it wasn't subtle. I can't feel any excessive play with the wheel off the ground. But I would be interested in any good way to test the ball joints. From what I've read there is some vertical movement to be expected on the TJ.

Tie rod ends were replaced a year or so ago, by the place I bought it from. Steering otherwise seems ok. I have aligned it since lift was installed. No sloppy steering, it responds to small input while going straight.

This thread details my suspension components and one of the issues I've been trying to diagnose. Except one thing I didn't mention in that thread is a new Currie track bar in front. Both axles now centered.

Tires are 30x9.5 General Grabber ATx, with only 5k miles or so on them. Balance is suspect, I need to have that checked.

Just rotate the tires and see if something changes.
 
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WallyWest

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Please define the "problems entirely" here.

Not being a goof but this is like someone saying I hear a faint rattle noise some place on my jeep. What is it.

I know, it's just hard to nail down any specific thing.

The thread I linked above is one of them, a flat spot on the tire thump from the rear when cold at low speed. Goes away when warm.

I believe Blaine describes it as running over a quarter and being able to tell whether it's heads or tails. Basically every tiny imperfection in the road seems amplified. And I'm in PA, our roads suck, lol. I can feel the same bumps in my '08 GC with 130k miles, but they're much more subdued. I know some of that is the different kind of vehicle, IFS, all that.

I sometimes have a rocking chair feeling, like the axles are fighting each other or something. That has gotten better as I've replaced suspension components, but it's still noticeable.

Randomly it will pull a bit under braking. Rear brakes have been replaced. But it's not how hard I brake that's the issue, it really feels random. Not a hard pull either, just enough to notice. I was wondering if some play in the control arm bushings could cause that. I've tested it on empty roads from like 50mph hard braking and letting go of the wheel. No problems. When I did the rear brakes I flushed all the lines too. Could be a sticky caliper but it's also not always the same direction. Sometimes it pulls left, sometimes right.

The one thing I did solve with the front track bar was a bit of death wobble at freeway speeds. But I still have vibration above 55mph. It comes and goes, but I have stock gearing so I don't think it's driveline. The frequency is more an out of balance tire kind of thing. I believe it's more prevalent, even trigger by, acceleration. Seems to calm down when cruising at a constant speed. In any case I start to notice it approaching 60mph. One theory I have is that it's the same rocking chair thing I feel at lower speeds, just sped up.

Basically I'm trying to decide what to replace next. The rear control arms that I removed were definitely old, but the bushings weren't in horrible condition. Some cracking, but no major deformation or tearing. If I replace the front control arms and not much changes I'm pretty much down to the axle level. Maybe driveshafts, but the angles I have right now are very slight. The rear is almost completely straight.

All of this has somewhat improved as I've swapped things out, but I feel like all I'm doing is masking the problem and I haven't found the root cause yet. And it's probably multiple problems not just one.

Rotating the tires to see if anything changes is a good call though, I'll try that.
 

Rubicon John

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Have someone wiggle your steering wheel and see if the steering box input shaft is wiggling with the steering wheel while the output and pitman arm stand still. If this is the case the box might have a small amount of slop.

remove front driveshaft and take it for a drive to see if vibrations persist. If so, reinstall and then remove rear shaft and drive in 4hi to see if vibes persist.

Diagnose, don’t throw parts at it. However, if the Jeep has some miles and wear on it, it could certainly be a few things contributing to your issues.

Mine needed several things replaced to get the ride quality where I wanted it. That came with the higher mileage I bought it at.
 
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Rubicon88

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I know, it's just hard to nail down any specific thing.

The thread I linked above is one of them, a flat spot on the tire thump from the rear when cold at low speed. Goes away when warm.

I believe Blaine describes it as running over a quarter and being able to tell whether it's heads or tails. Basically every tiny imperfection in the road seems amplified. And I'm in PA, our roads suck, lol. I can feel the same bumps in my '08 GC with 130k miles, but they're much more subdued. I know some of that is the different kind of vehicle, IFS, all that.

I sometimes have a rocking chair feeling, like the axles are fighting each other or something. That has gotten better as I've replaced suspension components, but it's still noticeable.

Randomly it will pull a bit under braking. Rear brakes have been replaced. But it's not how hard I brake that's the issue, it really feels random. Not a hard pull either, just enough to notice. I was wondering if some play in the control arm bushings could cause that. I've tested it on empty roads from like 50mph hard braking and letting go of the wheel. No problems. When I did the rear brakes I flushed all the lines too. Could be a sticky caliper but it's also not always the same direction. Sometimes it pulls left, sometimes right.

The one thing I did solve with the front track bar was a bit of death wobble at freeway speeds. But I still have vibration above 55mph. It comes and goes, but I have stock gearing so I don't think it's driveline. The frequency is more an out of balance tire kind of thing. I believe it's more prevalent, even trigger by, acceleration. Seems to calm down when cruising at a constant speed. In any case I start to notice it approaching 60mph. One theory I have is that it's the same rocking chair thing I feel at lower speeds, just sped up.

Basically I'm trying to decide what to replace next. The rear control arms that I removed were definitely old, but the bushings weren't in horrible condition. Some cracking, but no major deformation or tearing. If I replace the front control arms and not much changes I'm pretty much down to the axle level. Maybe driveshafts, but the angles I have right now are very slight. The rear is almost completely straight.

All of this has somewhat improved as I've swapped things out, but I feel like all I'm doing is masking the problem and I haven't found the root cause yet. And it's probably multiple problems not just one.

Rotating the tires to see if anything changes is a good call though, I'll try that.
Oh boy...
Lots of things..
Could be...

Brakes not feee flowing why the darting at times...
Front axle u joints absolutely could make your vehicle dart if brakes applied and if they are not rotating within the bearing caps freely anymore.

Tires...tires have a tremendous amount of feedback!!!

Drive shaft u joints can give you described issues.

What you are describing isn't your wheel bearings. I highly doubt that anyways.

Sounds abd vibes over the intranet are really hard to diagnose
 
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WallyWest

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Well, U joints are relatively cheap and easy to replace. That had crossed my mind as well.

Oh, and FYI I'm running my tires at 26 psi. No signs of uneven tread wear.

So does this seem like a reasonable plan going forward?

Rotate tires, drive it a bit and see if any changes. If so, get tires really well balanced.

Pull front driveshaft, see if anything changes. Replace U joints while I have it out.

Reinstall front, pull rear. Same deal.

Then front axle U joints.

While I don't typically like the throw parts at it approach all this stuff is on my list of things to replace just because of age and mileage anyway, so whatever.
 
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T Crawford

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I had a front break pulling and after talking with mr Blaine (just had installed his front and rear pads) his suggestion was caliper rebuild kit from Napa or such, pop out the piston and reap lace dust boot and seal, did that and my sticking caliper stopped. I only have 35k on mine