Leaking input seal on JKUR NV-241OR transfer case?

Mudskipper

2nd Time Around
Member 2022
Did all new drivetrain fluids on the Jeep today (no idea if previous owner ever did them, so it seemed like a good idea to just start everything over at 50k miles). So I did both diffs, engine oil, manual transmission fluid and t-case fluid.

Noticed a “sling line” of ATF residue coating stuff in the area of the front of the transfer case, where it bolts to the back of the transmission. No “active” leak, but definitely evidence of one at some point.

Hmmmmmm ok.

Pulled drain plug for t-case, and got maybe a bit less than a quart out of it. Ok, so I guess once it leaks down to 45% of fill volume, it quits leaking, lolz. Reminds me of helicopters. When they STOP leaking, they’re out of fluid! So I topped off the t-case with 2 quarts of ATF4, and put everything back together. No leaks observed…. Went for a drive later, and it’s definitely leaking pretty good while underway. Lots of newly splattered/slung ATF in the places that had the “old” residue earlier.

Anyways, looks like it’s coming out of the little drain hole at the bottom of the front of the t-case, right where it bolts to the back of the transmission. It only drips a little when it’s not running, but by the amount of stuff slung all over underneath, it’s a pretty good leak when its being driven.

Will probably rig up a Go Pro camera and go for a drive sometime this week and see if it can catch it in action and see where and how much volume the leak is.

I’m thinking maybe front input seal, but I’ve never had a t-case out on any of the Jeeps I’ve owned, so I can’t say for sure. It’s definitely not in the rear, and it doesn’t appear to be the front output seal either, the boot for the Rzeppa joint thingy is nice and clean. Wondered about speedo gear housing, but it started to rain and I ran out of poking around time.

Anyone ever have this issue with their t-case leaking at the front input where it bolts to the transmission?
 

Gr8Dain

Board of Directors
Member 2022
VA4WD
Did all new drivetrain fluids on the Jeep today (no idea if previous owner ever did them, so it seemed like a good idea to just start everything over at 50k miles). So I did both diffs, engine oil, manual transmission fluid and t-case fluid.

Noticed a “sling line” of ATF residue coating stuff in the area of the front of the transfer case, where it bolts to the back of the transmission. No “active” leak, but definitely evidence of one at some point.

Hmmmmmm ok.

Pulled drain plug for t-case, and got maybe a bit less than a quart out of it. Ok, so I guess once it leaks down to 45% of fill volume, it quits leaking, lolz. Reminds me of helicopters. When they STOP leaking, they’re out of fluid! So I topped off the t-case with 2 quarts of ATF4, and put everything back together. No leaks observed…. Went for a drive later, and it’s definitely leaking pretty good while underway. Lots of newly splattered/slung ATF in the places that had the “old” residue earlier.

Anyways, looks like it’s coming out of the little drain hole at the bottom of the front of the t-case, right where it bolts to the back of the transmission. It only drips a little when it’s not running, but by the amount of stuff slung all over underneath, it’s a pretty good leak when its being driven.

Will probably rig up a Go Pro camera and go for a drive sometime this week and see if it can catch it in action and see where and how much volume the leak is.

I’m thinking maybe front input seal, but I’ve never had a t-case out on any of the Jeeps I’ve owned, so I can’t say for sure. It’s definitely not in the rear, and it doesn’t appear to be the front output seal either, the boot for the Rzeppa joint thingy is nice and clean. Wondered about speedo gear housing, but it started to rain and I ran out of poking around time.

Anyone ever have this issue with their t-case leaking at the front input where it bolts to the transmission?
I just resealed mine at the same spot last weekend. But not the same transfer case. I am run ing a dana 300 on my CJ. But same leaky spot for sure.
 

Mudskipper

2nd Time Around
Member 2022
Did you pull the driveshafts and shifter and take the case off, or just smear some RTV up in the hole? Because that DID cross my mind…
 

Gr8Dain

Board of Directors
Member 2022
VA4WD
Did you pull the driveshafts and shifter and take the case off, or just smear some RTV up in the hole? Because that DID cross my mind…
I removed the tcase and pulled the input shaft out and used black rtv to create new seals. I only wanted to do it once. Mine leaked a lot. Even when sitting still. I also replaced the trans output seal while I had the transfer case off.
 
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Gr8Dain

Board of Directors
Member 2022
VA4WD
That is a bad leak. And your transfer case uses ATF? I think I read that above. I see you (or someone) pulling that transfer case to find/fix that leak.
 
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