Now that the shaft was made up, there was still the problem of how to manage the case connections. I could have put a double-bearing carrier and yoke on the front an overdrive and mounted it after a short drive-shaft, but I wanted an integral mount. I had my broken cast-iron T-10 tailshaft and I scrounged through my junk pile for a T-86 main case. I then spent many happy hours on a Bridgeport mill making most of these two parts into piles of cast iron chips. When done, I had a very short T-10 tailshaft, with a flat surface exactly parallel to the front surface, right behind the rear motor mount boss. I made even more of the T-86 case into chips - I reduced it to a flat plate consisting of only the original rear of the case. I had a very good professional welder (who also did my shaft) use nickel rod to weld the two cast iron components together. I aligned them in the machine shop and delivered them to the welding shop clamped together. With a long bead on the outside diameter there was a lot of weld. I was not there to observe the welding, but I assume the entire assembly was pre-heated.

I then assembled the 4-speed and overdrive. It worked great - best of both worlds, but there was one lesson to be learned. The original design for all these Borg Warner overdrive transmissions includes a “gutter” cast into the main case. This gutter catches gear oil thrown from the gears and it is carried back into the heart of the planetary gear assembly. I thought if I filled the overdrive through its separate fill hole, it would have adequate lubrication. Well, I was wrong. After about 4,000 miles, the overdrive started “singing”. The sump level in the main case was much lower than the overdrive and slowly the oil all ended up in the front case. For the next 4,000 miles the solution was to top off the overdrive before making a highway trip. Finally I tore it down and put a seal between the cases. This was easy because there was a bearing bore that was empty, so all I had to do was press a bushing on the shaft and turn it true to the seal’s ID and find a seal with the appropriate OD.