Transmission oil pan conundrum.

[dodgemahal]

I was watching a YouTube channel recently and a guy(Uncle Tony) said synthetic motor oil can seep through gaskets made of cork. I wondered if this can apply to synthetic transmission oil as well. I changed transmission oil on my '67 Coronet A727 using a Mahle brand gasket, which is cork with a steel carrier. Right away it started to leak along the forward edge of the pan. I'm using valvoline synthetic. I'm extremely meticulous about these things and think I did everything right and to spec. Anyone else experience this? Any favorite gasket brand? Looks like I'll have to start over, dang it!

 

[dadsbee]

Are you sure it's the pan?.. and not the dip stick tube O ring, or shifter shaft seals.

 

[PurpleBeeper]

There is no chemical/physical reason why "synthetic" trans oil would leak more or less than conventional trans oil

 

[Darter6]

gasket brand?

Get a factory Mopar 46RE pan gasket. Costs about $30. Some guys swear by them.

Are you sure it's the pan?.. and not the dip stick tube O ring, or shifter shaft seals.

Deffinitely check these.

 

[GTX JOHN]

We use 46RE gasket.

 

[493 Mike]

I'm using cork with Mopar ATF+4 and no leaks.
Mike

 

[MoparLeo]

150 inch pounds.

 

[dodgemahal]

Does anyone use a gasket dressing like Indian or permatex? Both are non-hardening and tacky. I usually do, and as I said, I've done many of these and this is my first leaker.

 

[toolmanmike]

Does anyone use a gasket dressing like Indian or permatex? Both are non-hardening and tacky. I usually do, and as I said, I've done many of these and this is my first leaker.

A good gasket and a flat pan doesn't need sealer. You can put sealer on the pan side of the gasket but you'll need an air chisel to remove it one day.

 

[Darter6]

Mike,a good soak with brake clean loosens that stuff up.

 

[toolmanmike]

Here's a thread I started for 904 pans and gaskets. Old Torqueflites can use the same pan and gasket as the later model overdrives. Heavy gauge steel, a drain plug, and extra capacity are all plusses. The newer gaskets are very high quality, are silicone coated and have a steel core. They are reusable. Deep 904 transmission pan?

 

[Darter6]

Just a FYI. Ma Mopar only used silicone sealer and no gaskets on the 80's Dodge Omni's automatic pans.
I worked at a place that had a fleet of Omni salesmen cars that we serviced.