90 350 tranny- weird problem
 

:eek: bought a used tranny and installed. put new filter and pan gasket in. Problem is when the car gets hot tranny oil is leaking out around gasket and pan. I don't see any oil coming down from anywhere else. Have any of you guys seen a problem like this? Tranny works fine but oil runs out every 100 miles. What would cause this?????

Overtightened?

If the transmision has a breather hole it might be obstructed. I have no idea one way or another if it has one. The transmission might pressure up a little otherwise. Test with the dipstick removed perhaps if it does not blow oil out. Or perhaps if it does any other method on the transmission to equalise pressure is blocked.

If you have the old transmission still around have a close look at it. Or at a good transmission manual. Pan leakage once hot should not be an internal issue I would expect.

Sounds like your leak is very heavy once the transmission oil gets hot. Could still be the pan/gasket/transmission seal I suppose as well. Still I would not expect heavy fluid loss with no cold leakge at all present. You have looked for a crack in the transmission casting? It might expand and leak heavy once the case heats up.

It is as mentioned on an earlier post also possible to distort the pan flang by overtightning. You may have the pan from the old transmission to try to torque down properly if this is the issue. If not you can lighly hammer the original pan flange back to flat carfully sometimes. A good refferance is to use a sheet of old glass to examine if it is then flat. You can observe the repaired flange through the glass or just use this to check the present one to see if it is already flat.

putting pan on off old tranny fixed problem, thanks