Need some help with a 95 Tahoe 4wd, 4l60e & NP241c

[dkknaebel]

I have a 95 4wd 2 door Tahoe with a 4l60e and a np241c. I have had a persistent leak out of the rear output shaft seal since I replaced the motor and got it back on the road. I have replaced the seal twice. I have had a new driveshaft built. Slip yoke inspected and it is fine and within specs. I have replaced the front input shaft seal on the t-case. I have replaced the gasket between the t-case and the transmission. I have replaced the bushing in the extension housing. I cannot for the life of me figure out where the fluid is coming from. It is leaking out of the weep hole in the rear output shaft seal. I cannot think of any more seals to replace. When we had the t-case out, we scrubbed it down (this thing was buried in Tennessee red clay mud and I've been steadily chipping it out from under the trucK), we made sure the vent tube was clear and not clogged. There is no sign of leaking from the t-case itself.

I cannot figure out how the fluid is getting into the t-case. The gasket between the t-case and transmission doesn't have silicone or anything on it, just the fel-pro gasket. The extension housing has silicone on it where it mates to the back of the t-case. The only thing i can think of is the rear output shaft seal going bad after having all the fluid pushed from the tranny to the t-case when the front input shaft seal was shot, but that doesn't explain why so much fluid is back there. T-case was refilled to the top of the fill hole.

Any suggestions or anyone who wants to buy this damn thing off of me and put me out of my misery are welcome.