TSB # 21-003-04: Leaking NV241 transfer case on TJ Rubicon models

So I’m back. I did the same thing as the OP and it did not work with the seal I used previously. I used the same seal that was previously in the case. I have a few proper replacements in the way. I’m curious though if my actual transfer case retainer may need to be replaced. Anyone have luck finding those?
 
JoeUtley said:
So I’m back. I did the same thing as the OP and it did not work with the seal I used previously. I used the same seal that was previously in the case. I have a few proper replacements in the way. I’m curious though if my actual transfer case retainer may need to be replaced. Anyone have luck finding those?
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My fix did not work either. Have not seen a retainer around as they are discontinued. Might have to go with an atlas sadly.
 
JoeUtley said:
Literally my worst nightmare of a response. I just paid 1400 for this case 😭😭😭
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Sorry to see you guys having this trouble. I would give it another shot with the new sealing washer. Also examine the retainer( I was calling it the extension) carefully to see if there is some problem with it. Make sure all mating surfaces are super clean upon reassembly and install the output shaft seal carefully. Definitely worth a few dollars in parts and some time to save your tcase.
 
Bud125 said:
Sorry to see you guys having this trouble. I would give it another shot with the new sealing washer. Also examine the retainer( I was calling it the extension) carefully to see if there is some problem with it. Make sure all mating surfaces are super clean upon reassembly and install the output shaft seal carefully. Definitely worth a few dollars in parts and some time to save your tcase.
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When my proper seals come in I will give it another go. I messed up installing a mopar seal. Then just trying to get my Jeep off our lift I put a seal I thought might work. I think it was a front output shaft seal. I used rtv on the splines of the shaft and on the outside of the seal housing where it presses Into the retainer.

this time I believe I will take the retainer off completely to remove the seal and install the new one. Also to see if I need to file it more for the pressure relief.

I also replaced the speed sensor with a camshaft sensor after being recommended to do so by advanced adapters. That didn’t work and I also have no speedometer. At least my mileage won’t go up I guess!
 
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Bud125 said:
Sorry to see you guys having this trouble. I would give it another shot with the new sealing washer. Also examine the retainer( I was calling it the extension) carefully to see if there is some problem with it. Make sure all mating surfaces are super clean upon reassembly and install the output shaft seal carefully. Definitely worth a few dollars in parts and some time to save your tcase.
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I used all the parts mentioned above, even a new washer. My leak is coming from the VSS hole and leaks down onto the skid plate. Idk if that helps explain why it may not be working?
 
chill_RN said:
I used all the parts mentioned above, even a new washer. My leak is coming from the VSS hole and leaks down onto the skid plate. Idk if that helps explain why it may not be working?
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Well that's a bit different. I think there is an o ring that helps seal it in there, is that in good shape? How about the t-case vent, maybe plugged and building pressure? Is the VSS still an available part, could you replace it? You have probably already checked these things just throwing some ideas out there.
 
Bud125 said:
Well that's a bit different. I think there is an o ring that helps seal it in there, is that in good shape? How about the t-case vent, maybe plugged and building pressure? Is the VSS still an available part, could you replace it? You have probably already checked these things just throwing some ideas out there.
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Unfortunately I have. The sensor was discontinued in 2014 but I found one that hadn’t been used on eBay and it still leaked. I also can’t imagine the slot got clogged as it leaked immediately after cutting it into the rear retainer. My only other idea is to find something to completely seal the sensor to the tcase and see if it leaks anywhere else.
 
chill_RN said:
Unfortunately I have. The sensor was discontinued in 2014 but I found one that hadn’t been used on eBay and it still leaked. I also can’t imagine the slot got clogged as it leaked immediately after cutting it into the rear retainer. My only other idea is to find something to completely seal the sensor to the tcase and see if it leaks anywhere else.
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Try cleaning the hole that the sensor fits into. Any spec of dirt can cause a leak. The VSS gasket is probably just a viton O-ring. Peel it off the sensor and bring it to a parts store. They can probably match it up to something stock. Or, you can probably order one from McMaster, if you know how to measure an O-ring (hard because they are so flexible).

The other thing to check is the vent, like @Bud125 mentioned. If that vent is plugged, the case can build pressure and that will force oil past the seals.
 
So I wanted to get things fixed before I made my comment on this. First I purchased a new seal and added another cutout section to the retainer like Bud did. I put the first one in the wrong spot. So now I actually have cut a slot for the fluid to go back into the t case. Not leaks yet on the test run.

I haven’t had a speedometer since I got the 241. It had a bad sensor and if you look for the mopar part number for a speed sensor they are discontinued. What is not discontinued is it he mopar cam shaft sensor. I got mine on Amazon. It is working perfectly!
 
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Update: I took @Mike_H advise and found a larger o-ring for the VSS and used some permatex rtv to create a seal where the sensor and t-case touch. So far so good, took it about 60 miles last weekend with no leaks. Let’s hope I’m done with it for good!

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Anyone having any leak issues still? I am rebuilding a used 241 I picked up and noticed it doesn't have the drain back cut out on the retainer. Which brought me to this thread. I am thinking it might be a good idea to file one in like this thread mentions since I am rebuilding it. My case is a 2003 model.
 
So I found this oil drain back referenced in the 241or rebuild thread on this site. Link here. https://wranglertjforum.com/threads/how-to-rebuild-241-or-241or-transfer-case.44680/

This looks to be a jk case but they are essentially the same minus the speed sensor. I wanted to say it looks like the valley is actually at the 7 o'clock position with the extension housing installed to align with the oil drain back hole in the case.

Photos from the rebuild thread linked above show this valley and the hole in the rear of the case mentioning to align the two. You notice the jk extension which has this valley machined in is at the 7 o'clock position. Photos attached from the rebuild thread. The housing only bolts on one way and it looks like the oil drain back hole and valley should be aligned. I also attached where I filed my drain back extension housing as I am rebuilding an earlier Rubicon case and don't want any leaks. I filed enough to see into the oil drain back cavity with the housing installed. Doing so very carefully so I didn't crack or file through the housing. I tried to align the valley with a rib on the outside of the housing.

I will report back if this doesn't work.

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Longwhitejeep said:
So I found this oil drain back referenced in the 241or rebuild thread on this site. Link here. https://wranglertjforum.com/threads/how-to-rebuild-241-or-241or-transfer-case.44680/

This looks to be a jk case but they are essentially the same minus the speed sensor. I wanted to say it looks like the valley is actually at the 7 o'clock position with the extension housing installed to align with the oil drain back hole in the case.

Photos from the rebuild thread linked above show this valley and the hole in the rear of the case mentioning to align the two. You notice the jk extension which has this valley machined in is at the 7 o'clock position. Photos attached from the rebuild thread. The housing only bolts on one way and it looks like the oil drain back hole and valley should be aligned. I also attached where I filed my drain back extension housing as I am rebuilding an earlier Rubicon case and don't want any leaks. I filed enough to see into the oil drain back cavity with the housing installed. Doing so very carefully so I didn't crack or file through the housing. I tried to align the valley with a rib on the outside of the housing.

I will report back if this doesn't work.

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Figured I would report back in case anyone come across this in the future. These 241or cases are getting older now so I suspect a lot will need rebuilding. The drain back galley I filed into the tail housing seems to be working. I do not have any leaks or the rear output leaking.

It does have low miles since the case rebuild since this is a weekend wheeling rig.
 
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numb1jeepguy said:
I scrolled through it twice, and I never saw it. Maybe I missed it. I’ll look again later when I have more time. Thanks
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Im not sure it's there. Just wanted to make sure you saw more photos.

Typing "np241 exploded view" into google may help as well.
 
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