2000 XJ 8.25 Rear End

[XJ Zone]

So...onto my next problem...

I've been hearing a chattering type noise for the last couple weeks but I haven't had a chance to investigate
We'll I looked it over yesterday and I think it’s the rear end
One of the spider gears has a chip out of it and a hair line crack that’ll probably break off soon
Plus the real kicker, my carrier has quite a bit of side play

First off, does anyone have a set of spider gears, and possibly side gears, for a 29 spline 8.25?

Any ideas on the carrier play, could it be from the carrier bearings being worn out, or do I have bigger problems?

[C Monster]

just put a ford 8.8 in it john , it you can find a cheap one with the right gears and limited slip.

[Creepy]

Screw Adjuster Design: Oil the adjuster threads on both the housing and on the adjusters themselves. While holding the races on the bearings, place the carrier in the housing. Install the carrier caps according to the marks made during disassembly so that the threads are seated evenly on the adjusters. Third member differential designs require a 10 to 12 inch spanner wrench to tighten the adjusters. Chrysler differential designs require an extension bar and special spanner to access the adjusters through the axle tubes. Tighten both the left and right adjusters evenly by hand until they are fairly tight. If the backlash is too wide, tighten the left adjuster until the backlash is correct. If the backlash is too tight, tighten the right adjuster until the backlash is correct. If necessary, open one adjuster and tighten the other. Both adjusters must be fully hand tightened when acceptable backlash is obtained. The final adjustment should tighten the left adjuster since the ring gear is forced away from the pinion gear while under load.

Screw Adjuster Design
The easiest method uses screw adjusters to set the backlash and carrier bearing preload.
Carefully oil the adjuster threads on both the housing and on the adjusters themselves.
Note the order in which you tighten the adjusters so the backlash remains consistent, even
when subjected to heavy loads.
The pinion gear always forces the ring gear away from itself whenever it transfers power.
Start with a looser backlash setting than the axle’s manufacturer calls for and always
ensure that the last adjustment made to the left adjuster tightens it.
If the backlash becomes too tight, loosen the left adjuster first, followed by tightening the
right adjuster. To reestablish the backlash setting, tighten the left adjuster. Ensure that the
last adjustment made to the left adjuster tightens it to eliminate any space between it and
its bearing race. Any space or looseness on the left side will let the carrier deflect when
under load, and this will allow backlash to open up when driven under load.
Once the backlash approaches the manufacturer’s recommendations, tighten both left
and right adjusters evenly to increase carrier bearing preload. Set the carrier bearing preload
to approximately 150 to 200 pounds/feet. It is difficult to damage bearings with excessive
carrier bearing preload on a screw-adjusted differential.


I made 2 adjustment wrenches from two D-30 spindle nuts, two 3' long pieces of 3/8" black pipe and two 1/2" socket adapters, I welded the nuts to one end and the socket adapters to the other so I can use a ratchet or a torque wrench to set the pre-load.

Sounds like an old nut off a d30 shaft would work nicely then.

Some quick googlin'.

Its actually pretty easy to 'fix' your worn carrier bearings for a while, at least. (If you are lucky the adjusters just backed off.) I have done this a dozen times on Toy axles and they are fine afterwards.

The neat thing about this problem, is you can adjust it away. The pinion depth did not change, you just need to get your backlash spec back. Adjust the carrier over into the pinion and then set some preload again. Look up the backlash spec, and use a dial indicator on the ring gear teeth. you can do it by feel once you gain experience with what a couple of thousands feel like. Helps if you work with machine tolerances a lot.

So - fix your broken side/spiders. Make the tool with the nut welded on end. Adjust carrier bearings (backlash) and pre-load. You need a dial indicator to do the job if you have no experience building rears.

[XJ Zone]

Thanks Jan, I haven't had a chance to google it too much yet

Like you said, hopefully the adjusters just backed off

I don't have much experience with setting backlash, but I do have access to a dial indicator

Now to make a couple adjustment wrenches & find a set of side & spider gears

[The Garagemahal]

I have a 8.25 here from an auto $100 ( 29 sp ) 3.55 gears

[XJ Zone]

Sept 15, 2014 19:32:36 GMT -4 The Garagemahal said:

I have a 8.25 here from an auto $100 ( 29 sp ) 3.55 gears

That's wicked Scott

I've got a guy down the road that might have what I need

I'm gonna go see him tonight, but if that doesn't work out you'll be hearing from me

[XJ Zone]

Sept 16, 2014 8:00:03 GMT -4 XJ Zone said:

Sept 15, 2014 19:32:36 GMT -4 The Garagemahal said:

I have a 8.25 here from an auto $100 ( 29 sp ) 3.55 gears

That's wicked Scott

I've got a guy down the road that might have what I need

I'm gonna go see him tonight, but if that doesn't work out you'll be hearing from me

Got a new set of spider & side gears

Good to know you've got that though

Now I gotta get them adjustment wrenches finished tomorrow and should be good to put it back together

[XJ Zone]

I must have done something wrong...that was too easy

It's all back together and works great

Having the right tools makes it seem easy

But...that wasn't the noise I heard...it's the transfer case

Now I gotta figure that out...one thing after another

[XJ Zone]

Yeah...definitely the transfer case
Sounds like it's gonna blow up when put in 4WD
I don't know much about transfer cases but I'm assuming just replacing the chain isn't gonna do it
So...what's my best option...have mine rebuilt, buy a rebuilt one, or try my luck with a used one?

[C Monster]

The front driveshaft good , yes. I had someone bring me a jeep to work on one time
They said the tcase was shot, it was the CV u joints in the front driveshaft
Not much to a tcase very very easy to rebuild

[Creepy]

Easy to rebuild, and a chain might solve your problems if its just jumping teeth. The drives are pretty damage resistant.

What is the t-case doing? Big bang and momentary loss of forward if you give it a shot of fuel? Or a constant grind?

[XJ Zone]

It's definitely the transfer case

I had it up on stands after redoing the rear end and had it running in drive, front end & shaft not moving

With a slight amount of constant gas, you could hear it, and feel it, in the rear output of the transfer case

It's the same noise when on the road, a constant grinding

Based on the noise I figured that if it was the chain, the drives would probably be shot

But like you said the drives are pretty damage resistant, so maybe it just needs a new chain

I'm just a little weary of tearing it apart, it's my only means of transportation to work right now (10 min drive each way)

It needs to be fixed asap, I'm just hoping for not much down time

Anyone know the price of a new chain?

Am I better of trying that or just replacing it?

BTW anyone got a good NP231?

[jmurphy]

I have a couple of TJ 231s in pieces and a complete case from an 89 YJ (21 spline input). I'm in the valley near Berwick. PM once you know what pieces you need and I'll try and hook you up.

You should definitely disconnect the driveshafts and check for play in the outputs.

(Slip yoke in the rear? Does the fluid come out when you pull the shaft? I can't remember...)

[Creepy]

Doesn't sound like a chain problem.

Stretched chain just jumps teeth, it makes a wicked loud bang if you gas it. Just driving in 2wd there is no symptom. (chain does not have a load on it, is only spinning from front driveline turning, its physically disengaged from main shaft in t-case)

I'd check rear yoke runout and maybe pull the back half the case off and look inside.

[XJ Zone]

Sept 22, 2014 9:18:09 GMT -4 jmurphy said:

I have a couple of TJ 231s in pieces and a complete case from an 89 YJ (21 spline input). I'm in the valley near Berwick. PM once you know what pieces you need and I'll try and hook you up.

You should definitely disconnect the driveshafts and check for play in the outputs.

(Slip yoke in the rear? Does the fluid come out when you pull the shaft? I can't remember...)

Good to know, thanks bud, I'll have to figure out what I need

And yeah it's a slip yoke in the rear

Sept 22, 2014 9:46:11 GMT -4 Creepy said:

Doesn't sound like a chain problem.

Stretched chain just jumps teeth, it makes a wicked loud bang if you gas it. Just driving in 2wd there is no symptom. (chain does not have a load on it, is only spinning from front driveline turning, its physically disengaged from main shaft in t-case)

I'd check rear yoke runout and maybe pull the back half the case off and look inside.

See...I told ya I don't know transfer cases  but I'm willing to learn...the hard way I guess