727 transmission leak at bellhousing.

[Huicho417]

When I took my 727 transmission to get rebuilt I also added a Summit deep pan that adds 2 quarts. It shifts great and does not leak anywhere but a small drop every now and then out of the bottom of bellhousing. The car usually gets driven every other week when I am not driving my pickup truck. I know the converter drains back into tranny when it sits for a while. Having said that, could the two extra quarts/plus converter drain back be causing this issue? I read a post somewhere where the deep pan was recommended but only used the original 8 quarts of oil as noted on service manual.

 

[Cranky]

When I took my 727 transmission to get rebuilt I also added a Summit deep pan that adds 2 quarts. It shifts great and does not leak anywhere but a small drop every now and then out of the bottom of bellhousing. The car usually gets driven every other week when I am not driving my pickup truck. I know the converter drains back into tranny when it sits for a while. Having said that, could the two extra quarts/plus converter drain back be causing this issue? I read a post somewhere where the deep pan was recommended but only used the original 8 quarts of oil as noted on service manual.

Pull the front dust/dirt cover and see if the inside of the bell is wet. If so, your front seal is seeping....if you have a 'full' size converter, you will most likely will have to use a small paint stick or a long Q tip to feel round for wetness.

 

[ruffcut]

I had a similar deal with mine and the 2 extra quart pan. Trying to keep it at the full mark would result in having fluid leak from the front and after trying to add and keep it at that level, I just left it at the level after it puked. The transmission works fine and it still has more than the stock required fluid, so I have been driving it that way with no further leaks. I'm sure you know the breather is in the front also and when the fluid is at operating temp it may leak some from there as well. JMO ruffcut

 

[Huicho417]

I had a similar deal with mine and the 2 extra quart pan. Trying to keep it at the full mark would result in having fluid leak from the front and after trying to add and keep it at that level, I just left it at the level after it puked. The transmission works fine and it still has more than the stock required fluid, so I have been driving it that way with no further leaks. I'm sure you know the breather is in the front also and when the fluid is at operating temp it may leak some from there as well. JMO ruffcut

This makes sense to me. I did add a little last time I checked it and the stick showed low. Maybe is should have left it since it was still running fine. I will leave it that way and hopefully it will stop as some point.

 

[Cranky]

This makes sense to me. I did add a little last time I checked it and the stick showed low. Maybe is should have left it since it was still running fine. I will leave it that way and hopefully it will stop as some point.

A little bit low with a deep pan is ok....

 

[dvw]

Full is full on the stick regardless of pan capacity. If it leaks out he bell housing there aren't many possibilitys. Front pump seal, pump gasket, pump o-ring. Cracked or worn converter hub. Damaged pump sealing surface of the case. Overheating causing flow out the vent. Pump seal and converter hub wear are the two most common.
Doug

 

[TJP440]

DVW pretty much covered it. Full is full on the stick regardless of pan capacity.
A deeper pan just holds more fluid it doesn't raise the level.
Could also be the Low/Reverse pipe plug in the lower L (drivers side) of the BH,or bolt sealing washers as well but those are unlikely

 

[Dave6T4]

Like DVW said. Not his first rodeo! I have used LUCAS leak stopper with good success in stopping various small drips.

 

[Cranky]

Like DVW said. Not his first rodeo! I have used LUCAS leak stopper with good success in stopping various small drips.

I used brake fluid in of one mine....the sucker is still going and not leaking but I did change the fluid shortly after adding it and that was probably 15 years ago. No, never did work at a used car lot