Mechanic says noise from D35 rear end = locker going bad? ...Opinions?

[tokarev]

I have a 2001 XJ Sport 4x4 that came straight from a Govt auction (US Forest Service - Oregon). It has 100k miles and is all stock except for some fender trimming and 31" tires, which I put on last year (~10k miles ago).

I recently started getting a bad "rubbing" noise from my rear end (Dana 35) when making turns. The noise is similar to a muffled version of rubber tires chirping when making tight turns on dry pavement.

I took it to the local Pep Boys, and was shocked when the mechanic told me my REAR LOCKER was going bad!!??... I told him I didn't have one, but he insisted that was the problem, and maybe one had been installed at the dealer (in a Dana 35??).

So I took it home, jacked one rear tire off the ground, and gave it a little throttle to spin the tire. That reproduced the noise pretty loudly, but it never jumped off the jack (ie. no locker ever kicked in).

Any idea what's going on here? Does that mechanic not know what he's talking about? Is the open differential in my D35 going bad?

Thanks for your input.

 

[RCman]

...the local Pep Boys...

There's your problem.
I'd doubt it in an ex-service vehicle, but anything is possible with a used vehicle.

It is probably a bearing gone bad. At any rate, don't pay a mechanic to fix anything. Go grab a C8.25 from a yard for $100 and swap it in a long weeknight. Anyone with a basic set of tools can do this. This of course assuming you don't have/care about ABS.

 

[XJLI]

Since its a forest service truck, it's more than likely got a limited slip out back. But yea, somethings shot regardless.

 

[tokarev]

Since its a forest service truck, it's more than likely got a limited slip out back.

Forgive the newbe question, but I'm a little confused? I do not have the "True Trac" model, so do you mean it might have something like a detroit locker in the rear?

 

[souske]

First mistake- going to pep boys for service
Just get a different axle (8.25, 44, 8.8) the D35 sucks big floppy donkey dong

Hey, you asked for opinions arty:

 

[XJLI]

Forgive the newbe question, but I'm a little confused? I do not have the "True Trac" model, so do you mean it might have something like a detroit locker in the rear?

You sure it's not limited slip?

 

[tokarev]

You sure it's not limited slip?

I always assumed it wasn't... How could I tell for sure if it is or not?

 

[Lowrange2]

Pull the cover off and look at it. There's a pretty significant visual difference.

 

[SanDiegoOverland]

Yup, I've seen a few forest service rigs with a LS in the rear to help with slip on unsealed, wintery roads.

I don't know how he'd know that 100% without pulling the cover, though.

 

[RollTider]

X3 on the 8.25. Just get some new Ubolts and bolt it in.

 

[tokarev]

Well, I guess I just answered my own question...

I found this post on another website:
http://www.jeepforum.com/forum/f11/how-do-i-tell-if-my-differential-limited-slip-1090082/

And.. Check out the sticker I found inside my glove box!... I guess I DO have a Limited Slip in my D35. Unbelievable...

OK, now for the next question: How do I get it to quiet down when making turns? Is the LS clutch fried, or does it just need some additive in the gear lube?

 

[souske]

You could throw a bottle of friction modifier in it, LS need it to help the clutches glide.
I don't run any in my 8.8 LS, because it helps them grip better offroad.

 

[kastein]

If it's shot you can simply put new clutch packs in it, 4wheelparts has them for like 58 bucks. It's not all that hard to do.

Pep boys will hire damn near any idiot...

also seconding the 8.25 suggestions if you are considering replacing the whole rearend. Buy an 8.25 for 100 bucks, new ubolts (they are a different size), and a driveshaft from the proper year range / engine / transmission / rearend donor. I am betting you have a 4.0/auto like 99% of the people on here, you probably want a driveshaft out of a 96-01 4.0/auto/4x4/c8.25 equipped donor if you swap to an 8.25.

If you don't care about the limited slip working, you can simply run it the way it is, since it didn't walk off the jack, the clutches are almost certainly completely worn out. A worn out limited slip is just a fancy open differential.

 

[sidewaysstarion]

well don't the true tracs like to spit out their clutches when they wear out and tear up the ring and pinion?

 

[ChiXJeff]

A True Trac is a helical gear limited slip, no clutches in these. A Trak Lok (Jeep OE) is a clutch type. No, the clutches don't get spit out & tear up the r&p. When the clutches wear out, it just runs like an open diff.

 

[ChiXJeff]

tokarev, did you happen to change the diff lube just before the noise started?

 

[tokarev]

tokarev, did you happen to change the diff lube just before the noise started?

No, but I noticed the noises shortly after pulling a heavy u-haul across several states.

Now that I think about it though, I was short on time, so I took it to a wal-mart for an oil-change and lube check right before I left with the u-haul.
The receipt doesn't say that they changed the rear fluid, but maybe they did... Either way, it sounds like changing the rear fluid and putting in LSD additive will be my first course of action. It's kind of embarassing, because It sounds like my cherokee is going to break down every time I make a turn.

If that doesn't help, looks like I should be shopping for a decent 29 spline chry 8.25 axle to swap in... Problem is, I have dreams of 33" tires, gears, locker and a lift in the future...

 

[ChiXJeff]

Definitely drain & refill the diff, with the LSD additive. If you've got any thoughts of larger tires in the future, don't drop anything more than the oil change in the D35.

 

[tokarev]

Bummer... I just called all the local junk yards, and the best deal I could find for a Chry 8.25 rear axle was $300 for one from a 1999 XJ with 92k miles on it.

That seems kinda high, what do you guys think?

 

[souske]

The only yards that know what they have are going to be expensive. You want to find a U-pull it yard, and gamble the $2 entry fee to fins out if they have one.

As for finding one closeby, I would check with your local chapter.