I am finishing up the restoration of my 1950 Chevy 1/2 ton with a three speed transmission and have a small annoying leak of gear oil at the slip joint housing. I installed new gaskets in the ball joint housing and slip joint. It does not appear to be leaking at the ball joint housing. I am scratching my head trying to figure out where this leak is coming from as it would seem to me that if a seal in the transmission was leaking it would leak out the ball joint and I don't see how the gear oil could leak past the universal joint. Prior to the restoration I do not recall a leak at this location so I did not tear into the transmission and replace the seals in it. I have the original enclosed drive shaft and I am wondering if the leak may be from the rear end housing working its way up from there. I drained the transmission and measured 20 ounces oil which is a little less than what the drivers manual lists as it capacity. Any thoughts? Thanks. Mike