xj00

I have a 2000 xj with the 231 tcase. 4.5'' lift 33s. 8.25 rear. SYE, shims blah blah blah. About a year ago I bought a 97 xj with the manual trans. My auto trans was weak and Im more of a manual fan so I did the trans swap to make it a manual. A friend of mine that works at a shop did the swap and put the SYE in there while he had it. All was going good for about 6 months.

One day I was playing on a snow day and I started to hear a loud whining/bearing noise. Knowing my axle ujoints were shot, I replaced those and the noise still persisted. Brought it into a nearby reputable jeep shop (dude built a commander up with an LS swap - things nasty) so needless to say they know what theyre doing. He put it on a lift a quickly noticed the Tcase had a good amount of noise coming from it and perscribed a rebuild. Said whoever did the swap put gear fluid in the tcase and that most likely toasted it after 6 months of driving. He did the rebuild and the jeep ran flawless and made no noise - until I put it in 4wd. No abuse whatsover - never even wheeled the new tcase at all and it made a real bad grumbling noise when put into 4wd. Brought it back to the shop (about a month or 2 after his rebuild) and the took it apart. He said there was water in there and bearings had rusted out and seals were shot. He says all the seals and bearing were replaced and tcase was cleaned and had correct fluid. I have no clue how water got in the tcase from not wheeling it. Drove it on pavement in a few rainstorms but no wheeling - let alone in any water. I was extremely confused on how water would have gotten into it. He thought I had it submerged and didnt want to warranty it. We came to terms and he rebuilt it again a week ago. Said this time he put a new chain in, new bearings, seals - everything including a new fork bc the old one was toasted Still had a bearing noise but they were confident it was something else - I wasnt convinced but they just did a 2nd rebuild so I thought id drive it for a bit and see if it gets worse.

I took it out this weekend and went through a creek crossing (not a technical one at all - jeep could crawl up in gear and not die). Under load in 4wd i hear a few loud pops what sounded like it was coming from the tcase going up the other side. Went to another place that the 4wd would be under a load going up an incline and heard/and felt the same few pops. 4wd did work, but I had never heard that noise out of my jeep. (and I have wheeled this thing HARD in the past well before my manual swap). It clearly isnt right and I know they arent going to be happy to see my xj roll into the shop tomorrow.

I know they know what theyre doing so my question is - could this nonstop issues have something to do with the manual swap I did and something not being exactly compatible? I didnt ever have any issues before that manual swap and wheeled it hard for years. Havent really wheeled it much or hard after that manual swap and it seems to be having issues. And now with the rebuilt tcase for the 2nd time its still doing weird things/making sounds.

Im a bit stumped and dont want to have these guys keep rebuilding it (even tho its under warranty) if there is an underlying issue. I mentioned the manual swap to them, but they didnt seem to think anything of it. Any suggestions?

Thanks in advance.

caged

the popping sounds like maybe the chain is slipping. that's really all that's in there, other than the gears the chain runs on.

if you need to pull it apart, you should try it yourself, they are really simple inside, watch bleepin jeeps video, that will get you right through it with confidence.
fill with regular transmission fluid.

tinytrax78

mine had a worn shaft bearing causing a loose chain, at first look I thought the chain had stretched but really it was just a bad bearing (mine was popping and whining also)

4.3L XJ

Rule of thumb for any chain and sprocket combo from chainsaws to cars. If you have a worn chain, then you have worn sprockets. You have to change the sprockets when you replace that chain. Sounds like that was never done. If you put a new chain on worn sprockets, it will stretch very quickly. Personally I would not put any more money or time into this tcase and get one from a wrecking yard and just put in in. The 231 tcase generally will last a good 300k+ and not need more than an oil change

xj00

chain slipping is what I thought initially. But being in the jeep hearing something is pretty tough to pinpoint. I'll tear into it this weekend and check into the bearings and chain.

tinytrax78

ill tell you this there is no mistaking the chain slipping it is loud as heck and you think its coming thru the floor !!

xj00

looks like somehow a 242 chain got put back into the thing. Getting put back together now and hope all will be good.