D30 rebuild

im putting a "new" D30 into my XJ and am giving it some TLC first. ive got some sanding and painting, 4 ball joints, 2 UCA bushings, all new steering, and some other little odds and ends to do. its a '90 axle (jeep had a 242, so its non disconnect) and the unit bearings are shot. which is ok, as i plan to install my good ones and stronger shafts from my '97. when i removed the units/shafts i noticed the shafts were a little grooved, so i decided to do the axle seals as well for good insurance (ive got almost $300 in new parts into this SOB). looking closer i see a LOT of dirt and grime inside the axle tube...

is this normal?
how can i clean all this out before installing my shafts?
is the axle seal different between the two years?











i know this seems like a lot of work for a stock axle, but my manual has 3.07s, and the 3.55s have been an amazing help in gas mileage. ive already swapped the rear. i cant imagine what 4.56 or 4.88 would do. ive never driven a truely low geared jeep. im only on 245/75R16s (rubicon take offs). when it comes time for new tires i know 33s will suck again... but now ive got a set of axles to build in my spare time without the jeep being down. and these ones should last a damn long time, which is good with me being a "poor college kid". lol.

Well, with diff cover off, spray the crap out of the inside with brake clean. I believe the seals are the same, IIRC

Pop the differential and post a picture of the axle tube inside.

Clean the tubes just like a gun barrel, only think 3" instead of .22.Rags and a rod.
I would up grade the unit bearings if possible to the year of your XJ,if possible,it would keep things like brake parts simple to remember.Your going to need to pull the carrier to do axle seals,so you can really get it clean..

ehall said:

Pop the differential and post a picture of the axle tube inside.

Click to expand...

will do...

Wayne Sihler said:

Clean the tubes just like a gun barrel, only think 3" instead of .22.Rags and a rod.
I would up grade the unit bearings if possible to the year of your XJ,if possible,it would keep things like brake parts simple to remember.Your going to need to pull the carrier to do axle seals,so you can really get it clean..

Click to expand...

hadnt thought of it that way... lol.





this is the first time ive taken an axle apart this far. old '90 unit bearing are in the trash. im going to install my '97 unit bearings and stronger shafts.i shouldnt need to swap knuckles right? i should be able to just swap my rotors and calipers? i figure, im this far... itd be dumb not to pull the carrier and replace them considering how cheap they are.

I can't help on the hubs, other than to say that you may need to swap brake parts too, but I'm not sure. Search

I just swapped in a replacement D30. The carrier popped right out with a little crowbar action. One of the tubes had nasty corrosion inside, and it had worked up under the seal.



I used a 2" wire brush on a 90-degree drill adapter to clean out the tube at the ends. Other people have used wire brush attachments on angle grinder but I got further with this setup. I couldn't find an extender that would work or I could have used this all the way down.



Here's how it cleaned up the seal area

I also made a scrapper to remove the mud/rust/lube. Think "D" shaped ,with a 1/4 "all thread " rod attached plus a coupling nut to another piece of all thread for extra length .

VAhasnoWAVES said:

i shouldnt need to swap knuckles right? i should be able to just swap my rotors and calipers? i figure, im this far... itd be dumb not to pull the carrier and replace them considering how cheap they are.

Click to expand...

the rotors need to match the bearings and the calipers need to match the knuckle-- I don't know when the 2 piece AMC knuckle changed to the newer Chryco design, though.


edit-- it looks like calipers and knuckles changed after '89-- should be same units for your axles.