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Chr 8.25 rearend

Brian Carpenter

NAXJA Forum User
Location
Vermont
I lost a pinion bearing (at just 45k miles) in a "99 XJ. It has the Chrysler 8.25 rear in it... Got it out OK, the bearing seized and spun on the pinion heating and scarring it quite efficiently.
So the pinion is too damaged to re-use. :rattle:
You can't buy just a pinion, so I just got in a whole new ring and pinion.
I am familiar with the Dana/ Spicer stuff, but not this Chrysler which utilizes a crush bearing... Anyone have insight :lecture: or tips to do this swap right?
 
Where in Vermont are you, Brian, and what's your schedule on doing this? The reason I ask is that the procedure in the factory manual for this stuff is pretty detailed, and the best solution would probably be simply to give or lend you the pertinent pages, either xeroxed or torn out of my already mutilated '95 FSM, and depending on the circumstances, it might even be possible to deliver, though mailing would work too given a little time.

I'm in western Rutland county. email me. I never remember to check private messages here, so that's not very reliable.
 
You can use one of these downloadable FSM's:

---LINK REMOVED---

Here's the rub, I believe the way you have to do it is this:
Put the rear end on jack stands. Take the rear DS off and put a torque wrench on the pinion nut and measure the resistance as you turn the wrench. If the bearing is messed up that bad, you probably won't be able to get a accurate reading on the pinon nut. It's in the FSM, you just have to dig a little.

You can try calling your local tech dept at the dealer. They have been pretty cool about some odds and ends questions I have had. Maybe they could give you a ft/lbs setting.

I can certainly understand your wanting to help, but even linking to a downloadable FSM is enough to get us trouble under copyright law. Even a "cold" (cut-and-paste) link.

Now, if you have the FSM, you can re-type the information and present it that way - that falls under "fair use," and it rather safer. The information isn't what's owned, it's the presentation of the information. I've dug into that for use in building my "Tech Archive" - since it's all derived from FSM and other manufacturer's literature.

Copyright law is a strange creature - my wife has been dealing with it (in a corporate setting) for the last 15 years or so, and she still doesn't understand it all.

Please
DON'T LINK TO DOWNLOADABLE FSM's NO MORE! I like this place, and I'd like to see it stay around... If you research "fair use and copyright law," you might find it instructive...

5-90
 
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balloo93 said:
You can use one of these downloadable FSM's:

--- LINK REMOVED ---

Here's the rub, I believe the way you have to do it is this:
Put the rear end on jack stands. Take the rear DS off and put a torque wrench on the pinion nut and measure the resistance as you turn the wrench. If the bearing is messed up that bad, you probably won't be able to get a accurate reading on the pinon nut. It's in the FSM, you just have to dig a little.

You can try calling your local tech dept at the dealer. They have been pretty cool about some odds and ends questions I have had. Maybe they could give you a ft/lbs setting.

I think he's in deeper than this, because he has to replace the whole ring and pinion, and that may mean resetting everything, even though he isn't replacing the diff. side bearings.
 
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Dont mean to be negative, but that crush collar is a B!+C# to set. I had a 6' long cheater bar on that thing for like 40 minutes going 8th turn by 8th turn trying to get it to seat. Just one tip: Im not sure if this is the way everyone else does it, but use your old pinion nut to tighten down on, and when your positive that its ALMOST completely torqued, take it off and use your new pinion nut to do the final torquing. That way you dont put so much freakin stress on the new one, in case it strips. Which HAS happened.
 
I hereby affirm that the chrysler 8.25, though stout, is un-repairable in your garage.. Take my advise and take it to the dealer for locker install, ring and pinion, everything... ! :wierd:
The crush collar is too dificult. it requires specialized tools, as well as for setting the carrier bearing preload. :lecture:

IF YOU HAVE PROBLEMS WITH IT, SCRAP ONE OFF OF A JUNK JEEP!
IT COULD COST ABOUT $500, BUT THEY WILL BE SET UP BY THE FACTORY - PROPERLY.

OTHERWISE FIND A SERVICEABLE D-44.. YOU CAN WORK ON THOSE. EVERYONE CAN! :repair:

IMHO of course.... :)
 
Not trying to hijack the thread, but if the 8.25 is too difficult to work on even for people who know what they're doing, is putting in a No Slip or Aussie (if/when they ever make a 29-spline version) going to be too difficult? I change my own gear oil and I've rooted around in the diffs so that I can at least identify things when I need to, but I've never changed a set of gears or anything like that.
 
Timber said:
Not trying to hijack the thread, but if the 8.25 is too difficult to work on even for people who know what they're doing, is putting in a No Slip or Aussie (if/when they ever make a 29-spline version) going to be too difficult? I change my own gear oil and I've rooted around in the diffs so that I can at least identify things when I need to, but I've never changed a set of gears or anything like that.

Just the sheer length of the cheeter bar makes if a nitemare on the ground. In the vehicle I'd want it up at least 5ft on a lift and even thats scary once you start torqeing the pinion nut down. Freaken XJ really moves around. Mechanic friend of mine who is really good with gears has 4 ajustable floor screw type jack stands that can go up to 6ft high and once he gets it up on the frame lift he puts one in each corner so the XJ is supported in 8 places, 4 on the lift under the rocker panel area on the lift points and 1 in each corner to keep it from getting squirrley. I still have to get my gears done and I have no intention of tackling that part of it, while doing a locker, lsd or axles is relatively easy that pinion is a whole other story... I sure would not want to be laying on my back torquing that pinon down with it on jack stands with your feet up against a tree or something solid for leverage, uhuh, not me...
 
thought not a 8.25 it is a D35 here is how my one friend does his rear in his driveway

28100_1671-med.JPG


this is for holding the yoke and pinion as you tight and lossen it .


28100_1672-med.JPG


here it is being used to lossen

28100_16791-med.JPG


and here it is being used along with a cheater bar to tighten it up
 
I like it cept for the 2x4's on the top of the jack stands, too easy to slip off, thats the reason the top of the jack stands are curved to cradle the axle not hold a flat topped 2x4....
 
hey i didn't say i do things this way.i saw that as i was posting and was going to mention something about i don't condone that type of thing but .i figured most poeple would know better.i really don't know why they would be there what is the 1 3/4 inches going to get ya.
 
Yes it really is too difficult for home repair. You have to torque 3-ways at once.. the pinion bearing preload is in the neighborhood of 250 lb most torque wrenches only go up to 170 or so. and then you need to have 2 wrenches in each axle tube tightening the carrier bearings athe same time because that iss how you allign the carrier. Its confusing, but IMHO, you are better off paying the dealership the $500 or more to add a limited slip.

-sucks, but its really for the best.. I tried the home shop route and my DD was laid up for three weeks (parts, tool build, 1st, 2nd attempt, tow to dealer, dealer work) It could have been 3 days with a warrantee!
 
Check your local driveline shops, their prices are generally much lower than the dealers and they will put in whatever you want vs most dealers w/oem parts. I'll have to dig around but I remember my auburn being around $450 or so installed, that included all new bearings, seals and the auburn, lube and friction modifier, it took about 2 hours start to finish. The best part is I got to help and actually take it apart and put it back together while he was fitting the auburn in the case, took some grinding so it was in and out 3x and I even learned some tricks like the passenger side adjuster, screwing it all the way back into the cap housing, putting together the tool for doing the adjustment using some 1" electrical conduit and a bolt welded in, driving it for 5 miles after refilling the diff because when you remove the axles alot of fluid in the tubes is lost. What to look for when painting the gears and using the gauge to adjust backlash. Just a whole bunch of stuff that makes the 8.25 and 9.25 so different [the 9.25 is actually easier to work on, both adjusters screw all the way back into their cap housings] While now I would have no fear removing the auburn, axles, etc I would not touch that pinion at all, I watched them doing a regear on a 9.25 on the lift next to me. Thats one of the reasons I'm going back there to get my regearing done when I get the money...
 
nfw
 
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I actually bought the factory oem tool that has a cross shaped "+" cut-out, one for the 8.25, the other for I don't know what, certainly too large for the D30.

Those homemade pix gave me the idea on fabbin' the other end just for the D30 size.

Still wondering what the other opening is in the cross shape :eyes:

Thanks, a most productive thread :kissyou:

btw, I'm doing this in my garage, with all the warnings, especially Richs', going to find some scrap 4x4's and snug 'em laterally between each wheel and the wall (with a "t" to catch two studs), so the xj can't tip off the jack stands. I actually did this to adjust my track bar way back when, with a small bottle jack rotated 90* to coax the t/b nicely into alignment.

A mind is a terrible thing to, uh, :anon: and I replied to the wrong thread...
 
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