I've got the suspicion I've bent an axle shaft... Are their any tricks to figuring this out without pulling the shafts? I'm so tired of wasting $40 in gear oil and resealing the cover every time I need to work on it.... PITA.

 

Rear axle:
Jack up the axle and pull the wheels.

Start it, run it, watch the flange.

Front axle:
Pull the shafts and lay a straight edge on it.

 

Just to clear a few things up...

- When you say "Pull the rear wheels" You mean to pull them out until they are tight on the c clips?
- When you say "Watch the flange" What are you referring to?


Thanks for the reply. I'm really hoping this is something simple and cheap... I've snapped two D30 axle tubes already. Both snapped right where they connect to the diff... Worst part is, they both happened from all the pot holes in this awful state.

 

I had a bent rear axle shaft (chrysler 8.25 )
I jacked it up, put jack-stands under the rear axle, set it on the stands.
put wheel chocks under the front wheels.
Put transmission in neutral(so you dont have to push the brake to take it out of park once it is running)
pulled the suspect wheel off, and brake drum.(do NOT touch the brake pedal after pulling the drum, you'll pop your wheel cylinder seals out, and fluid all over)
Started the jeep, put it in gear. look at the axle flange, and see that it is not spinning true.
Shut vehicle off in gear. wait for spinning things to stop, then put transmission back into park.
re-assemble drum and wheel.
I bought a whole 8.25 rear end off Craigslist for $120
You can use either side axle shaft, and I have another spare.
Keep in mind '96 and earlier used 27 spline axles. '97 and later uses 29 spline axles.

 

Blue...

 

Ok, I've got it.

Two reasons I think I've got a bent shaft:

- The Jeep "wobbles" back and forth up intil about 40mph, then it smooths out into more of a vibration. It's a definite wobble... Feels almost like a tire with a flat spot, but not as rough.

- I've replaced axle seals twice and they haven't held either time, so either something is bent or the bearings are shot, but everything feels tight and I'm not getting any noise out of it.

 

Jack up the front.
Push/pull the top of the tire toward the engine and back toward you.
Any movement indicates a bad unit bearing hub.

 

I actually just replaced my front wheel bearings Saturday. I'm extremely versed on wheel bearings and my Xj goes through them quickly. My short arms are pretty much maxed out as far as suspension angles go. Every time I hit a bump it's like being kicked in the chest by a horse. The Jeep feels that much more than I do and the bearings are the weakest part. Timken has a 3 year warranty and they don't question replacing them, so I'm not complaining too much. I've searched high and low for aftermarket units but haven't turned up anything.

 

Guess I'm missing something.....if you jack up one wheel and spin it, I would think it would wobble if the axle or flange was bent. Like when you are heating a drum for removal.

 

It's not bent enough to show like that.

 

You would want to rule out a bent wheel, which would have similar symptoms. Thats why you want to remove the wheel, and brake drum, and look at the axle flange itself.

 

That makes sense. Does anybody know anything else that could cause this?

 

Again I seem to be behind the curve. Are you having vibration from a rear wheel? I just had a case where no amount of balancing would get it all the way smooth. Not bad but not perfect. Finally I swapped all four wheels with another Jeep Nice and smooth......I had used (cheap label), fix-a-flat more than once, (2?3? times?) Saw on another post that THAT might have been why it never would balance.

 

I doubt its unbalanced tires. My Jeep physically wobbles while I'm driving

 

Sounds like you are looking for run out and it is bested tested with a dial indicator.

Does anyone know how much is too much or the specs on this?