I was riding at Choccolocco mountain yesterday with a few buddy's when my trans made a grinding noise and stopped pulling while trying to climb a steep hill. There was fluid everywhere on the ground and the 4wd shifter seemed to be stuck. I finally got it to pull in drive if you gave it a lot of gas after I put more fluid in it. My question is, what's the best year transmission that will fit in my XJ?

They are all the same. Aisin-Warner (AW4). They are extremely reliable and durable and rarely fail provided they are maintained.

So, I recommend another AW4. Not every AW4 will fit every 4.0L so someone else will have to chime in with spline counts by year and compatibility.

Thanks. I'm going to look around and see what I can find. I need to get this thing going so I can hit some more trails soon.

I did something similar once. I confess, with just a 1/4 mile to get it off my "main" gravel road. Waz after midnight. I walked home and all I could find was used (straight weight Castrol of course), engine oil.

I put the old 30wt in there, drove it home, then later fixed the broken lines. It was again about pumped out, so I just filled properly with Dexron III, and never looked back. I think I've done about another 10K on it since then, over 283K on it now. It seems fine.

I never "baked" it. (OK maybe just a second finally getting in my driveway). The AW-4 is tough to kill! I wouldn't give up on it too soon.

Like F1 says, at some point they went from 27 to 29 splines on the output shaft. That should be searchable...without knowing I do know there were allot of other changes between 95 and 97 XJ's.

Howdy Jeff...what? Soft yellow tires and hard red ones? Man...that seems jacked up.

^This (except don't use 30wt unless it is all you can get), it is possible you just blew a cooler line or something, don't write the trans off yet, like everyone said AW4s are tough to kill.


Since you said your 4WD lever is stuck it is also possible the issue is with the transfer-case rather than the trans (the transfer-case takes trans fluid as well), while the transfer cases in the XJ are very strong/durable the aluminum housings have been known to crack when hit on rocks (why you should have skid plates if you play in the rocks) and a loose chain can also wear through the case eventually.


You'll need to crawl under it and take a good look at everything before jumping to any conclusions.

I had missed the 4wd shifter seeming stuck. Let's hope repairing broken cooler lines and a fluid change, or a few will do it!

I used a Dremmel cutting wheel and 3/8 fuel line to "repair" my lines. Finding, buying, installing new metal seemed unpractical for me. They are not supper high pressure. I DID use two little clamps mounted opposite, (because of the little flat spot), on each of the 4 connections.

Btw it seems on my 90, if the RF wheel gets hammered up hard enough, it's possible to mash/sever both of the cooler lines, up where it's not so easy to see or reach.

Just another voice for the AW4 trans being the best for the 4.0 and XJ both quite strong.

Thanks for all of the replies. I was able to get it in the shop and on the lift yesterday. There was no fluid to be found dripping from anywhere. I did drive it around in the pasture for a bit just to let it warm up and see if anything changed. It did go into 4wd and did pull, but as the temp warmed up the trans seemed to start wanting to slip whether is was in 4wd or not. When I pulled it back into the shop and crawled back up under it, I could see fluid coming out from between the t-case and the trans. When you first put it in gear, it take a second for it to start pulling. I am thinking that maybe the rear seal on the trans went bad and then the temps from wheeling that morning caused the fluid to leak out while going up the hill and it did hurt the trans. I bought a trans yesterday also. Its from a 99 model with 124k miles on it. Maybe this one will work.

The only advice I can add is to possibly avoid installing an AW4 from a donor Jeep that has a tow package. If a PO of the donor did a lot of towing, the trans could be further down the road of its life that the odo miles would indicate. Towing is tough on a trans. I used our 90 XJ to tow a 4000 lb boat and trailer. Up lots of hills too. The towing power of the XJ is deceiving. It will do it, seemingly with ease. But it shortens the trans life. In retrospect, that is probably why the AW4 in my 90 XJ died at about 225K miles. My current XJ has more than that on it and is running just fine. No tow hitch in its life. Just some thoughts from the field.