t90/d18leak

I just reinstalled and refilled my t90/d18 assembly and it is leaking at the mating surface on the drivers side. It has a new gasket. I filled the assembly through the transmission to the bottom of the filler hole and it started leaking at the mating surface so I took the filler plug out of the transfer case and quite a bit of 90W ran out. It stopped leaking but now the trans oil looks to be low. Any hints on how it can leak at the mating surface? I did not see any cracks in either case when I had them apart. The jeep is in the shop on a level floor so I don't think I overfilled it. Suggestions?

 

The T-90 and Dana 18 share oil, so if you fill one you fill the other. The transfer rate between them is fairly slow though.

As I recall, there's just a gasket between the cases. No reason why it could not leak like any other gasket.

 

I had a problem similar to this not long ago , i forgot to seal the bell housing to the transmission, sorry i misunerstood your talking about leaking between transmission an transfer.

 

When you mate the cases together there is a metal piece that keeps two rods in place. Mine was slightly cocked and kept the case from fully mating even though from first apperance the case looked fine. I had to grind the edge a tad and it sealed fine. Don't know what the rods are called but they were around half an inch in diameter.

 

Sounds like you are talking about the cluster gear shaft and reverse idler shaft. There is a metal retainer between them to keep them from rotating in the case. You can usually just reposition the retainer for clearance.