Rear WJ discs... Compatible with 8.25?

Many thanks to 1fox2go and his father for providing my axles (HP30 and 29-spline 8.25"), now the teardown and build-up process can begin



Now I managed to luck out and find a local man parting out a 2004 WJ who will sell me anything I want for any price I ask (seriously) so long as I pull it. I'm already grabbing the complete front brake/knuckle/steering setup (how does $80 sound?) and got to thinking about the rears...

I know these came with D35C and D44 rear axles from the factory, the latter of which has 3" axle tubes much like the 8.25" (right? or am I totally off base on this assumption?). Is there a decent chance that the emergency brake/caliper mounting brackets will fit over the 8.25" axle tube AND stock bolt pattern, and still work with the stock 8.25" axle shafts? I'm thinking this may be an apples-and-oranges discussion (as I'm sure the axle shafts are different as well as spacing/tolerances in just about every other regard), so please feel free to smack me back on track so I can stick with the KJ rear disc swap as originally planned.

Let me know your thoughts. Thanks!

Campbell

On that same note, if it's an I6 model then it came with an NV242... Would that be a fit into my 2001 XJ? I might have hit a goldmine here - looks like 2004 was a good year for WJ's in terms of parts

242 should bolt up though I thought WJs had the 249... check it over but if it is the 242 I haven't heard any reasons it wont bolt up. Be aware that you have to hack and tap the 242 for a SYE as you can't find a replacement shaft for the things.
Get the WJ control arms, too. Depending on the year of your jeep, get the brake booster / master cylinder as well.
I don't know about the rear brakes... I say pull em' and let us know what you find out.

Thanks for the input. He pulled the engine as a donor for an XJ apparently, so the case is out of the car and ready to roll. I, too, was under the impression that WJs had 247s or 249s (which they indeed do), however, most (fixed that) I6 models in 2004 were 242-equipped:

http://www.wjjeeps.com/tcases.htm

I think I'll take some measurements on my spare 8.25 to see whether or not the hole pattern for the backing plate for the rear brakes is even compatible before proceeding down that route. Given how uncharted that territory is 5 years after the demise of the WJ, I get the feeling that it's not an easy (or feasible) swap. We shall see... The donor WJ in question has a busted rear axle (at least as far as the owner knows, he thinks it might just be a control arm problem), but if the axle itself is indeed broken it was likely not a D44.

I have a 2001 XJ, so I don't believe I'll be needing a booster or master cylinder upgrade in this case. If I'm wrong, please feel free to let me know

One more question on the 242, though... Will the shift linkage be correct or acceptable for use in an XJ, or will I just have to find out the hard way?

The WJ D44 is usually a D44a (aluminum casting) as I recall, so it's not impossible that the rear axle is broken. PS, this means you don't want it, even if it isn't broken... yet!

Definitely grab the LCAs off the front if you can, they're great for guys running a couple inches of lift with 30s/31s/32s who are having issues with their tires rubbing the LCAs at full lock.

Grab the front seats if they're in good shape and you can get a good price on it.

Forget the rear brakes, get yourself explorer rear brakes for your 8.25

don't the Liberty disk's both right up? They were 8.25's, so they ought to?

Mike H. said:

don't the Liberty disk's both right up? They were 8.25's, so they ought to?

Click to expand...

Yup. The Libby 8.25 is a bit wider than the XJ 8.25, though, and has coil spring brackets on it. Easier to swap the brakes than the whole axle.
'Course, if you were looking to link the rear... could go WJ front D30 and Libby 8.25...

I'm pretty sure that if it's a selec-trac that it's a 242 case. If it's a limited with all-trac (think that's what it's called) then it should be a 249 case. 249 case isn't bad, but I know most WJ guys swap to a 242. As for the rear diff, if it's an inline six, odds are it's a D35. Most of the D44a's came in the V8 models, they were in a very I6 model's from what I've heard. Not sure if your planning on running the WJ disc's, but if you aren't aware, they're bolt battern is 5x5.

I was also under the impression that the WJ D30 was wider then the XJ D30? Not to mention that's it's low pinion too.

Not all KJs have discs, there is a row of them at my local yard that have drums in the back, someone already pulled all the disc setups