My '48 pickup with a three speed has a transmission leak. It is leaking from the back of the transmission box where there is a shaft that comes out of the box to hold the counter gears. There is a pin back there holding it all together. Apparently the transmission box is just plain worn out so there is not a tight seal anymore. When you switch gears the shaft has a lot of play, and oil just seeps out. I would not mind a few drops of oil, but this leaks pretty badly. Has anyone had any experience with leaks like this. I believe I am looking at parts 7155 and 7140 on the diagram below. http://www.vanpeltsales.com/FH_web/F...truck-3spd.jpg

 

That would be the reverse idler shaft. I would drain the trans, clean the area around the shaft with a good solvent (like brake parts cleaner) and then cover it with a quality silicone. Won't solve the slop in the case, but should stop the leak.

 

I have never serviced one of those transmissions. That being said, all of the transmissions I have worked on have had a seal, o-ring or something to keep oil from coming out if they protrude from the case.
If it was designed to have such a tight fit that it would not allow oil to leak out I would think it would not wear out simply because it would not squirm around. If it does have an o-ring it may have came apart. Post a picture if you can and I'll see if I can give you better help.

 

It could be either the reverse idler shaft or the mainshaft (cluster gear) shaft, both poke out of the end, but they should be covered by the rear bearing retainer? I'd be surprised if the reverse shaft got enough wear to leak. No O-rings on either. You could bush the hole but it has to be bored precisely in the right place or the trans will never be right. The inside surface on the mainshaft is the thrust surface and they frequently get scored; VanPelt offers a rebuild service for cases that would fix all of it (Ford Three Speed Transmission Repair), he sleeves the hole and provides a hard steel thrust surface. Good cases are cheap, hell, whole trannies are cheap because everyone wants those newfangled 5-sp trannies. But the thrust surface could be shot on any of them...

Fiftysixford, they don't seem to have cared if they weeped, and mine actually leak very little. It's thick oil in there!

 

Well, they are a little before my time....