Rear tranny seal leaking. Help :S

[GUITAR1989]

So i bought a 74' C10 and noticed the rear seal on the tranny is leaking. its right where the yoke goes into the tranny. I repleced the seal and jacked the back of my truck up and its still spitting out fluid which is flinging onto my exhaust and smoking ....the guy i bought the truck from said he lowered it so im wondering if there is an issue with the tranny and rear end angle causing the yoke to spin at an odd angle and make a gap in the rear seal. anybody have any input on what the problem could be? i dont know much about vehicle repair so any help would be greatly appreciated

[Irish_Alley]

There is a vent hole in the yokesome say you can  some say not. There was a post not to long ago about this. I think it was vile who replyed how to fix this problem do a search. I can't cause I'm on my phone

[Captkaos]

You have to replace the inner seal to make it stop.

http://73-87.com/7387garage/drivetrain/yokeleak.htm

[GUITAR1989]

Right on thanks guys this is gonna suck but hopefully it stops the leaking...so should i plug up the weap hole in the yoke while im changing the rear seal? kinda seems like i shouldnt if its designed to relieve pressure...wheres the pressure gonna end up if i plug up its escape route. what would be a good thing to seal it with? 

[Captkaos]

If you are fixing it right, leave it open.

[GUITAR1989]

Hey guys im finally getting around to fixing my rear seal leak.  Ive learned a bit about my tranny since I first posted this topic. I remembered a little something that was over looked when my step dad and I replaced my rear seal on my th400. I saw an o ring on my yoke and asked him wat it was for. He said it was nothing and just brushed it aside and kept replacing my rear seal. Now I know that the little rubber ring sliding on my yoke was my tailshafts o ring   I havent been driving it without it so no further damage has been caused thank God. He told me my truck would be fine to drive leaking the way it was btw >.> Keep in mind this guy is my only source of info on fixing up my truck. Thats why I ask u guys as many dumb questions as I do. Cause when I ask em around here I get dumb answers that would probably damage my truck Do u guys know where I can get that o ring though. Ive been looking around and all I can find is complete th400 rebuild kits.

[Grim 82]

If you have the old one you can match it up at a parts store or hydraulic repair shop. If you don't have the old one to compare, maybe stop by a trans shop and see if they have it or at least have a kit they would open and let you measure it/match it. Or call somebody that produces or sells the rebuild kit and see if they can send you just that one ring.