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T-56 Leak

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Old 04-06-2008, 10:57 AM
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Default T-56 Leak

im having a leak issue at the tail shaft. i have changed the tail shaft seal several times, and finally gone back to the gm oem seal. that didnt work. anytime i drive the truck it leaks.

is there another seal in there that i have to replace?

my setup hasnt change since i put it together last year. and for the first 8-9 months no problem. then it slowly started to leak. and now its leaking to the point where im afraid of tearin something up. so any ideas or info on this problem would help alot.
Old 04-06-2008, 11:44 AM
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There's a bushing around the output shaft that maybe worn. This bushing it what keeps the output shaft rotating true and not wobbling. Otherwise there may be a groove worn into the yoke (unlikely) that the seal cannot mate up to and it causes the leak. Or the groove causes you to eat up the seal. I would put money on the bushing though.
Old 04-06-2008, 11:56 AM
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is the bushing something you can get to and replace from the outside of the tranny? like remove the rear seal and pull the bushing? or do you have to get inside the tail shaft section?
Old 04-06-2008, 04:39 PM
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well when it rains it poors. went to take a look at that seal and found this.....





so anyone got any ideas as to what is the easies way to repair this? can i get just a new cover or can i weld this one up?
Old 04-06-2008, 04:56 PM
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I would think a good experienced aluminum welder would be able to fix that. Try to find someone who works on airplanes or go to your local small town airport and ask around. That's how I got my boat fixed
Old 04-06-2008, 05:18 PM
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If I lived in your area and still had access to a welder I could fix it possibly, there may be something I am not seen in the pic. A lot of people will tell it can't be don't because it is cast. but they are wrong. I have fixed cracked transfer cases, wheels and intakes. ect...

But it should be able to be welded.
Old 04-06-2008, 05:20 PM
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i know supposely with cast aluminum you have to preheat the cast parts before welding or youll just make the crack run. but i didnt know if anyone had try it before.
Old 04-06-2008, 05:32 PM
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Originally Posted by RED04REGENCYRST
i know supposely with cast aluminum you have to preheat the cast parts before welding or youll just make the crack run. but i didnt know if anyone had try it before.
That is true. It needs to be preheated to about 500 degrees. and also it needs to be really clean. Preheating it also helps to burn off the aluminum oxide. If you prep it correctly it is almost as easy as welding regular aluminum.

If you take it top someone and they tell you it can't be welded because it is cast, just nod and smile and take it somewhere else. They are ignorant and will **** it up even if they attempt it.

BTW, I was a certified welder before I joined the Army.
Old 04-06-2008, 06:42 PM
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What he said. There are few that will do it and that is a good thing.

A repacement tailhousing may be with way to go as well. They are fairly common used. The main case is what brings the dough.
Old 04-06-2008, 07:24 PM
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That's a pretty easy fix. It should only take someone experienced an hour. I cracked a bellhousing once and it was a lot worse than that. I took it to a shop where they built vintage harleys for drag racing. They refuse to use new, non-vintage parts, so welding up cracked cast Al. was nothing to them since they're used to shattered cast Al. parts.


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