Here is what I have for seals.
there are 2 lip seals inside the 1st gen adapter.
here are the 2 lip seals.
transmission side
transfer side
here you can see where the 2 lip seals ride on the coupler
here you can see the sealing surface the o-ring on the t-case input shaft seals against. Make sure this side of the coupler is on the t-case side. Also, clean the splines on the coupler, and put some silicone on it. This will act as a back-up to the o-ring.
