Hi On a th350, will a front main seal leak from sitting for a long time, and then stop leaking after some use??? It seems that is happening to me. I filled the tranny and it leaked ou fast enough for me to see it. Now it seems to have stopped after I have used the car a few times. And yes there is still oil in it!!
Mike
1967 400 Convertible 1978 Firebird 1980 Trans Am Pace Car (Sold) 2002 Ram Air Convertible (Sold) Mike
I have the same issue with tranny fluid leaks. My TH350 will have no leakage problems for a while, but then when it sits, it seems to pour out. It is not coming from the pan, and seems to be coming from the front of the transmission.
my tranny guy told me that in the spring he gets alot of calls from guys who's trannys leaked over the winter,he said it's the oil draining out of the torque convertor and over filling the pan which in turn raise's the oil level to areas that are not sealed as well.once the car is started the oil gets pumped back into the torque convertor.
Trans seals do get hard, and when the converter's snout gets some wear they tend to leak.
Swapping the seal is a maintenance procedure, not hard but inconvenient. It's a must-do when the engine and trans are out for any reason, along with checking the converter for wear.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
I agree. These cars are forty years old. If the transmission is out for any reason, this is the time to replace all the seals. The same is true for rear axle seals and other seals as you go through the car. If you're going through rear brake shoes, take a bit of extra time and do the rear axel seals and put in new brake cylinders.
The rear main seal and transmission seal should be replaced when the car is that far apart because they are so cheap compared with the labor to visit the issue later. I think the same is true for transmission seals for the clutch packs. TH400 or Th350 seal service is simple work once it's on the workbench in front of you.
