I have a very small leak going on with the junkyard trans i just picked up. Its been in my truck about a month now and i never see any on the ground but i see just a drop or two around the tails haft seal every so often so i replaced it but i still get the drop. The fluid doesn't drop very low but i want to stop it before it becomes a big issue. I checked the shift rail plugs when i installed it and they aren't dry rotted and i resealed them with RTV and its totally dry up there. the trans is actually dry from the drain plug up. The seal with the tails shaft housing appears to be ok i can see the white seal all the way around and none of it is poking out. Im sorta lost on what to replace here?

 

Hmmmm..... Now you got me thinking! lol.

Only thing I can think of is possibly a bad drain plug seal? It's been a while since I drained mine, but I seem to remember seeing an o-ring or a washer crush seal. But I could be wrong.

Perhaps draining it, then sealing the plug threads with silicone, refilling and watching might be a good place to start. Seems you've covered the inspection pretty well.

Mine has a nasty habit of the case-to-tail housing seal being bad. That'll be fixed when my spare trans is repaired and installed sometime in the Spring.

 

I think i fixed it apparently there is a smaller seal that slides over the output shaft itself and seats down in a little grove mine did not come with one and had to do some digging at the parts store to find it luckily the guy behind the counter new what i was talking about and found it. Its been two days since i put it in and has appeared to stop. But its been raining pretty heavy so it may just be getting washed off ill watch it and keep you updated but thanks for the tip on the drain plug i may do that anyway when i flush it. I wanna put a few thousand miles on it to get any gunk out from when it sat in the warehouse.

 

ok got both seals back in and I'm sure its somewhere on the tails haft leaking. I see a slight oily haze on the slip yoke as well as some castoff on the cat. it has slowed down a lot with the new seal but still leaking any ideas? i used an aftermarket seal but it looks beefier that the stock one i took off. Any suggestions?