T-56 Magnum leak??

[CCT]

I have a new T-56 magnum that leaks at the tail shaft. We have replaced 2 seals and it still leaks. Only after a couple miles the bottom of the car is soaked.What else could it be leaking instead of the seal?Drive shaft angle is good. It has the correct amount of oil oil in it. Vent tube seems to be correct.

[dontlifttoshift]

Are you replacing it with the same seal? Tremec has a different seal that I would have thought to be standard by now.

Also, make sure it is not the shift tower. That's usually where they leak.

[CCT]

Thanks for your reply. We have put two different seals in. The first wasn't the right diamiater for the yolk. It it a transmission from Kiesler before the my went out of buisness. I called tremic and they said Kiesler was bad to chance some parts out on the tranny. So not sure where to start.

[parsonsj]

What Donny said: check your shifter. I'll bet that's the leak.

[sjaroslo]

I have a leaky T56 Magnum as well but haven't done the troubleshooting yet. If they DO leak at the shifter, what is the remedy? Just tighten up? Or apply silicone RTV? Or...? Thanks.

[ctcz28]

I have a fairly new T56 in a '69 Camaro with no leaks, so it is possible. I have the mechanical speedo and initially I did have leakage there due to what I consider improper crimping of the cable connection that I had to fix. I have the APT White Lightening shifter that I had to seal to the trans case, but there is no leakage. If you have the Tremec shifter, I can't help you with that. Is it possible that the driveshaft is a bit too short and the yoke is not fitting far enough into the trans tailshaft and as a result there is just enough wobbling to cause a leak but not necessarily be perceptible as a vibration? Tremec provides a spec as to the minimum the DS should fit into the trans tailshaft housing. If not using the mechanical speedo drive, is there any leakage from the plug at that location? What about from any of the electrical connectors? If the vent tube on the passenger side of the trans is crimped or pinched or the valve at the end of the tube is blocked or not open to the air the vapor pressure may be forcing fluid out the only escape route and that could be the tailshaft seal.

[parsonsj]

Here's a photo of the old (leaky) seal, and the new (non-leaky) seal:

https://www.pro-touring.com/threads/...72#post1160972

[Craig@Bowler]

I have a new T-56 magnum that leaks at the tail shaft. We have replaced 2 seals and it still leaks. Only after a couple miles the bottom of the car is soaked.What else could it be leaking instead of the seal?Drive shaft angle is good. It has the correct amount of oil oil in it. Vent tube seems to be correct.

Does it appear that it is pushing the seal out of the tail housing or forcing the oil out where the slip yoke contacts the sealing surface?

[CCT]

The first seal didn't wasn't the correct one and was too big for the slip yoke. It pushed it out. The second seal was tight but it looked like it was leaking where the slip yoke contacts the sealing surface. Thanks for the reply.