Greg11784

I have a 1996 Toyota 4Runner and a few months ago a car hit my on my passenger rear tire and now there is a wobble. We assumed that it was probably the axle shaft and the bearing. So we went and picked up a use axle shaft assembly (with brakes and everything still attached) and put that in the 4Runner.

However, we still have the wobble on that side. We know it's not the rim itself because we swapped tires on the rear end and the wobble remained on just the one side.

Do you guys think that we just got a bad used part or do you think that this could be something wrong with the 3rd member?

Also, after the swap, we saw this wobble while it was still up on jack stands before putting any weight on it.

BajaRunner

Eek, yeah, I had the same experience... except in Baja...noticed a wobble for about 15 seconds and then my rear wheel broke free of my truck and passed me by on the highway... not so fun.

One thing that comes to mind are the internal bearing and seal seats inside the axle housing. They could have been damaged, sheared, etc, causing the axle shaft to spin irregularly.

Even if the outside flange was bent, your wheel would just spin at an angle and not wobble.

I'd personally just get a new axle housing/assembly... I'm sure they wouldn't be too hard to get and not too expensive, considering the amount of front end collisions leaving the rear ends relatively unharmed.

Do you have a schematic of the axle to look at?
Dont know if this helps you but,
Rear Axle Shaft components: http://ncttora.com/fsm/2003/Repair_M...a/ras/comp.pdf
Differential components: http://ncttora.com/fsm/2003/Repair_M...3rz5v/comp.pdf

Greg11784

Hmm.. So you think that the housing itself needs to be replaced? If so I may as well get the whole new rear end.

I'm wondering if I can rule out the 3rd member or not. I could save some $$$ if I get the assembly without the 3rd member.

However, if the third member is the root cause I would rather put my old axle shaft back in and replace the 3rd.

4Crawler

iTrader: (3)

A bent housing would not necessarily cause a wobble, it would produce more of a lean to the wheel and tire. You can check the source of the wobble if you can jack up the rear end and secure it on jack stands and block the front wheels (assuming you don't have full time 4WD) and let the engine idle in 1st gear, watching the rear wheels turn. Since you have already seen the wobble, pull that wheel off and hold up a pointer to the rear brake drum and it rotates and see if that is wobbling. If so, likely that axle shaft is bent as well, or if you wanted to check farther, remove the drum and backing plate and see if the stub axle is also wobbling. Not uncommon for the semi-floating axle shafts to be bent, I have two bent ones on my '85 and have 4 more bent ones out in the back yard.

Greg11784

I still see the wobble when I take the tire off. However, I'm not sure how to test it if I have to take the backing plate and everything off. I would assume I would have to press that off right?

I'm still seeing the wobble with another axle shaft assembly so assuming that the used part I got was good, then I would assume that I've ruled out any of the axle shaft assembly problems.

However, if there is something I'm overlooking or more tests that I can do let me know because I'm stumped at the moment.

4Crawler

iTrader: (3)

How to remove the brakes/backing plate:
http://www.4x4wire.com/toyota/mainte...wheel_bearing/

cubuff4runner

When I bent my housing last year it made my tire wobble.

Greg11784

If the housing were bent would the tire rotate in a straight line? I keep thinking that if the housing was bent that it would just re-align the wheel off center.

Ultimately, If I have to go out and get a whole rear end including third member, then it should solve the problem. I guess I'm trying to see if I am forgetting to check something that would be cheaper to fix.

4Crawler

iTrader: (3)

Likely the 3rd member is OK, it only supports the inner end of the axle shafts. If you can find a local shop that can check the axle shafts for straightness, you could try checking those. Basically they would chuck the axle up in a lathe or holding fixture and put a dial indicator on the shaft and flange and see what the run out is. Then if the shafts are bent, replace them and if they are straight, see if you can replace just the rear housing.

cubuff4runner

As Rodger said your third member should be OK. Have you tried the axles on opposite sides, just as a test.

If you had a full float setup this would be somewhat true. The tire would just spin out of alignment, but wouldn't wobble. You have a semi-float so a bent housing can force your axle to want to bend, which will transfer a lot of pressure to the bearings. If the bearings have a little play in them it will be intesified with a bent housing making a minor wobble into a more intense wobble.

Greg11784

I ended up just getting another rear end and installed it.

So far it looks like the third member is alright out of the old axle. So the jury is still out on exactly what the problem is but it's gotta be the housing and/or the third member in this situation.

I thought about swapping the sides for a test. Maybe I will look into that while looking at the axle off of the vehicle.