73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: LTZ C20 on August 11, 2012, 08:26:38 pm
-
My 79 Cheyenne C20 has a sbc350 and a th350 auto, Couple weeks back I dropped the oil pan a put on a new one piece gasket. I also dropped the trans pan, put on a new filter and a new trans pan gasket. Now my trans is leaking. It has a small amount of fluid coming from the front edge of the pan, flowing across the bottom of the bell housing cover and coming to a drip right at the peep hole at the bottom of the bell housing cover which is the lowest point. I don't understand why it would do that with a new gasket. I used the gasket maker with the gaskets on both trans and oil pan.I also made sure that the trans pan bolts are all tight and I've wiped off the area a couple times and then looked underneath later to see where its leaking from but all I'm finding is the drip stream at the front edge of the trans pan. Everything looks sealed so I can't find it. Any idears ya'll have would be great. I'm pretty good with engines but not so much with transmissions hahaha.
-
Could it be using both the gasket maker and the gasket together causing this leakage? I put my gasket on without any gasketmaker, just the gasket itself. And the obvious, torque it to specs (google it, I forgot how much).
-
Is the pan flange flat?
The shift shaft seal leaking?
Sure its not the pump seal leaking, and running down to the pan flange?
-
Is the pan flange flat?
This is the most common problem I've seen with new gaskets not sealing
-
I'm pretty sure its the gasket, the trans didn't leak before. But it rally needed a new filter and now its leaking. Ive just been under it for an hour and I used some thick sealer I got from work, (GM engine sealer) and applied it to the spots that i think were the sources because they had fluid on them after I wiped everything off. I think the gasket was probably a little cheap and it just needed some extra persuasion to seal up completely.
-
The trans pan gasket should be installed dry with no additional sealer. Where did you get your gasket, I know that napa sells one that is like plastic and Ive had problems with those.
And I'm afraid to say but putting sealer on the outside isn't going to seal your leak.
A wise man (my dad) once told me silicone is just to fill the imperfections in the mating surfaces.
-
This is true, but thick gasket maker also works in a jiffy to seal up any fairly small holes or leaks, it seams to be holding now. I got my gasket from O'reilly but they said they hadn't had any complaints and the gasket looked like semi good quality. Oh well, it's sealed now and looks ok.