Help! Bent axle, busted wheel bearing?

mangle · 12-02-2007, 10:31 PM

Hello all!

I've got a 96 Grand Cherokee Limited. Last winter, while playing around in an icy parking lot in Boston, I put the right rear in to a curb. I was sliding at the time and pretty much hit the curb with the axle perpendicular to it. I wasn't going terribly fast (knee didn't even hit the transmission tunnel, and you have to look pretty closely to see the rash on the wheel).

In any case, the right rear started making a bit of noise after this. It's a swish sound at wheel frequency that gets louder in left turns and becomes a <thunk> at wheel frequency when the brakes are applied. At highway speeds, it seems to go away.

My question is, what is it, exactly? When I first heard it, I thought it was a warped brake rotor. This wouldn't be consistent with the curb tap. My second thought is a wheel bearing. I consider this most likely. The third thought is that it's a bent axle. The rear doesn't seem to vibrate, so I kind of doubt this one. How can I determine which of the second two it is, short of ripping the axle apart?

Thanks!

indept · 12-02-2007, 10:45 PM

Jack the rear up onto jack stands and run it in gear (this is assuming you can put your transfer case into 2wd) and see if either tire wobbles while spinning. If it's an open rear you can leave 1 tire on the ground & do this 1 tire at a time. Once again this is only if you can put your transfer case into 2wd

driabyor · 12-02-2007, 10:50 PM

drive and have someone watch the rear wheels...
jack up the injured side just enough to get a pry bar under .. then move the tire up and down. if it moves then you have a bad bearing
parking brake messed up..

mangle · 12-02-2007, 11:10 PM

Wow, thanks for the quick replies.

A little more information: It has 108k mi on it. It's a Limited trim and has all time 4wd. The options on the transfer case are 4 hi and 4 lo. I've had people watch the tire and have seen no motion in it. The vehicle tracks pretty straight but has started pulling to the right ever so slightly since tapping the curb. I know it probably needs an alignment. I yanked the tire off today to look at the brake rotor. It has no telltale signs of being warped on the front side.

If I do need to replace a wheel bearing or axle, how bad are each (I'd rather do it myself if possible)?

This is the first of several things I need to fix with my Jeep. Next comes the stereo, which refuses to receive fm channels (already isolated the problem to the head unit). Then there's a blown speaker. The list goes on... And my weekend toy is supposed to be the finnicky one!

alivenkickin28 · 12-03-2007, 09:38 AM

how hard did it hit??? i mean i wouldnt think it would have bent the axle by doing that --

Inavacuum · 12-03-2007, 11:28 AM

Quote:

Originally Posted by alivenkickin28

how hard did it hit??? i mean i wouldnt think it would have bent the axle by doing that --

I agree! I slammed into a ditch on a dirt road doing about 40 after swerving from a deer and it just barely bent my axle, but it was still enough to have to scrap it. I think you should have a look at those hub bearings. They're not hard to replace at all. Biggest ordeal will be breaking the bolts/nuts to get the old ones off if it hasn't been done in a while. Obviously an axle swap will be a little more in depth.

mangle · 12-03-2007, 02:44 PM

Ok, fair enough. With the tiny, tiny amount of damage to the wheel, I think it's safe to assume it's not an axle that's the problem. I'm going to more fully check out the brakes first before I think about ripping the hub apart. Thanks for the help!

**ArloGuthroJeep** · 12-03-2007, 02:50 PM

I HIGHLY doubt it is your brakes.

Inavacuum · 12-04-2007, 07:01 AM

Quote:

Originally Posted by mangle

Ok, fair enough. With the tiny, tiny amount of damage to the wheel, I think it's safe to assume it's not an axle that's the problem. I'm going to more fully check out the brakes first before I think about ripping the hub apart. Thanks for the help!

Its really not that big of an ordeal to get the hub off. Break the hub nut. Two bolts for the caliper, three for the bearing.

http://www.jeepforum.com/forum/f310/how-replace-axle-shaft-wheel-hub-bearing-assembly-w-pics-377208/

**ArloGuthroJeep** · 12-04-2007, 08:22 AM

Quote:

Originally Posted by Inavacuum

Its really not that big of an ordeal to get the hub off. Break the hub nut. Two bolts for the caliper, three for the bearing.

http://www.jeepforum.com/forum/showthread.php?t=377208

That is for the front...he smacked the rear axle.

mangle · 12-04-2007, 09:23 AM

Just thought I'd follow up... I jacked the rear of the vehicle up last night. There is a slight bit of axial play in each of the rears (meaning they will move in and out ever so slightly when you pull on them... maybe 1/8th inch). The axle bearings seem fine as there is no radial movement (side to side) or tilting. It doesn't seem that an axle is bent. The noise appears to be coming from the brakes, but because the axle has the axial play. The right squeaks when pushed or pulled. The left doesn't. I think my next activity will be to pull the brake rotors off and make sure that the hub bolts are tight.