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Leaking fluid help!!!

HoytBows

HoytBows

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Ex-Michigander, now Elizabeth Colorado
K guys was driving with the window down and smelled something a little funny so I crawled under my truck at the gas station and found it dripping tranny fluid. When i got home i did more detective work and found that its dripping from a hole in the bottom of the bell housing right in front of the tranny pan. There is a small aluminum cap looking thing with clips at 3,6, and 9 o'clock and thats were its coming from... Anybody deal with this before? My guess is that the input seal for the torque converter is leaking or maybe something from the fluid pump? (except i dont know where the pump is on these ally's)

Ethier way im guessing i'll have to pull the whole thing to fix it. :mad2:

Its leaking pretty steady too... Any input would be greatly appreciated.
 
Did you recently change the fluid to a different type? How warm were things when this happened? How many miles on your truck? How hard were you driving it? Did/does it still drive ok?
 
Yeah i had just put two gallons of Amsoil Torque drive in several months ago. I wondered if that did it. The tranny runs fine and I went on a 5hr road trip and it was only down about 1 quart when i got there. I never got the tranny warm enough to cause anything to happen. Theres just under 190k on my truck, as it says in the sig
 
When you say 1 quart low what do you mean? The Allison's are famous for pushing fluid out under the conditions you were in. I like to keep the fluid level at the very bottom of the hot area just for this reason. Check your fluid level on flat ground with the transmission at 170 - 180 fluid temp and it should be at the bottom of the HOT area and life is good. You might want to clean it up and see if it leaks anymore before you add fluid.
 
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No guys its not too full. The thing did not leak a drop until about two weeks ago. The truck hasnt leaked a drop its entire life. Last November I drained the pan, replaced the spin on and filled it back up with Amsoil Torque Drive. Magically two weeks ago it started dripping from the two holes directly in front of the pan in the bottom of the bell housing. It drips pretty consistantly while the truck runs from somewhere inside the bell housing.

When i put another quart in the fluid line was at middle of the "cold" marking and the truck was hot.

I'd almost bet the farm that the better fluid loosened the 190k seal that was in there and allowed to start leaking while there is pressure on the system.
 
IIRC, you aren't supposed to flush the Allison as it could damage the valve body and possibly create a leak. A little late for that info I know... This is a tough one. Did you pop that inspection cap out and take a look up there? See if it's leaking from the front seal while idling?
 
Yeah it was "flushed" at 150k before I owned the the truck. I know they guy I bought it from pretty well so I'll ask if it was actually flushed or what.

I did not pull the inspection plate off yet. I planned on doing it today, but we got BOMBED with snow last night so I'm going to wait until it warms up. It drips during and for a short time after i run it, everytime.
 
Sounds like a seal in the pump. This is not a very common problem, but it can happen. Unfortunately, if that's the case, you're going to have to drop the trans to replace it.
 
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