NP231 Transfer case drip on bottom of case

[98TJHP]

Hello,

I am so close to putting the tub back on after doing a complete frame swap and rebuild on the tub and I am having trouble with a slight drip on the transfer case. It is coming right at the bottom where the two halves of the transfer case come together. I am struggling with what to do to find the leak because its not coming out of the weep holes to show the input or out put shafts are leaking and its not coming from the speed sensor o ring. I am curious though if its just because the jeep has been sitting for quite a while causing it to slightly drip and once I get it back on the road it might stop on its own. I am just curious if its better to just pull the case now before the tub is on or is it an okay project to do after once I have it running again?

Thanks for all of the help!

 

[afusco1222]

I would pull the case now and reseal it. It would be a great time to do a SYE if you do not already have one.

 

[98TJHP]

I would pull the case now and reseal it. It would be a great time to do a SYE if you do not already have one.

I wasn't planning on doing the SYE since I am leaving the jeep stock height and all. Also would it be leaking between those two halves or is that not a spot where it would leak? If not would it be an input shaft seal and do you know the part number on that so I can get it from advanced or auto zone?

 

[CharlesHS]

Do a thorough cleaning of the transfercase and examine to see if you can determine where the seepage is coming from.
Without determining where the leak is located; disassembling the the case halves may not resolve your problem, but could create an additional leak.

 

[98TJHP]

Do a thorough cleaning of the transfercase and examine to see if you can determine where the seepage is coming from.
Without determining where the leak is located; disassembling the the case halves may not resolve your problem, but could create an additional leak.

Okay yeah I have tried to clean it the best I can and I am still trying to determine where it is coming from. I thought the same thing though I am concerned with splitting the halves if not 100% needed. Am i correct that if its leaking from the small weep hole its the input shaft and if its around the drive shafts its the outputs? I have read as well it could be a vent hose issue but not sure how to check that.

 

[CharlesHS]

Weep holes generally notify you of a leaking seal.
IF its around the driveshaft; its the Output Shaft seal OR a driveshaft yoke that has a dirty or burred sealing surface.
A leaking vent metal tube rarely occurs other than if the hose is dried out or has a hardened hose.

 

[98TJHP]

Weep holes generally notify you of a leaking seal.
IF its around the driveshaft; its the Output Shaft seal OR a driveshaft yoke that has a dirty or burred sealing surface.
A leaking vent metal tube rarely occurs other than if the hose is dried out or has a hardened hose.

Okay that’s what I was thinking! I’m thinking I’m going to pull of the transfer case since I’m going to guess it’s the input shaft since that seems the most common and hardest to do when the jeeps back together. I found a national seal part number 710928 should be the correct one. Anyone have experience with that?

 

[98TJHP]

I pulled the transfer case and there was only one drip in the area between the trans and the transfer case and it looked to have come from the transmission output seal and zero signs of leaking on the transfer case input seal. I know it’s my transfer case dripping because that’s the fluid that is going lower and not the transmission. Is it possible that it’s leaking from between the case halves?

 

[98TJHP]

I pulled the transfer case and there was only one drip in the area between the trans and the transfer case and it looked to have come from the transmission output seal and zero signs of leaking on the transfer case input seal. I know it’s my transfer case dripping because that’s the fluid that is going lower and not the transmission. Is it possible that it’s leaking from between the case halves?

I am however getting a slight drip of fluid from inside the transfer case spline that goes into the transmission

 

[98TJHP]

I found the leak! It is where the two halves of the case come together on the bottom where there was some corrosion. I’m guessing I need to split the case to fix this problem. Any tips on how to do that? Do I need to remove the yoke?