leaking transmission pan

[Alex Hayley]

So I have a PML cast aluminum transmission pan (http://www.yourcovers.com/transpan_9684.php) and grabbed a rubber transmission pan gasket from Autozone. I put the gasket on dry and torqued it to spec. I filled the transmission with Vavloline Max Life Dex/Merc fluid. However, the pan is leaking at the back along the gasket. There do not appear to be any instructions online for installing the pan. Should I use RTV instead of a gasket or use something other than a rubber gasket? Should I use a combination of RTV and the gasket?

[Sinister]

Rubber gasket should seal by itself. Check your torque again.

[cdowns]

are you sure you cleaned both mating surfaces good and did you check the new pan for casting lines and casting flash?// should b no problems with a good cast pan and rubber gasket

[Alex Hayley]

Pulled the pan and checked both the pan and transmission surface. Both are straight and clean. Put the pan back on and torqued to 12 ft lbs. The pan still leaked so I tightened just little bit more. The leaking slowed down but not completely. There is still a bit of seepage. I have a cork and rubber gasket on order and will try that one.

[jim zag]

Which transmission do you have?

[Alex Hayley]

I have a TH350.

[C20-67_N_MO]

Next time you have the pan off and clean of all gasket material, I would use a straight edge on the gasket matting surface to make sure its flat and level. Other than that I would contact the company you bought it from.

These covers do not look cheap! So they should have some kind of customer support behind them.

Good Luck.

[Alex Hayley]

I did check the pan and it was straight. I will have the pan off again tonight and will check the transmission. The customer support for the pan has been good. They did recommend a rubber/cork gasket which I will try tonight.

I did have a bolt hole in the transmission, in the area of the leak, strip out which I tapped to 3/8" and is fine now. I really don't think this is causing the leak though since I can get the correct torque on the tapped bolt hole.

[Wilson_]

I am having the same issue. Have you checked the shifter shaft o-ring? when it leaks it runs down to the pan gasket area and looks like a pan leak.

[Alex Hayley]

I have looked quite closely at the entire transmission but will check again.

[CEE1NG_RED]

Originally Posted by Alex Hayley

I have looked quite closely at the entire transmission but will check again.

Any follow up? Where was the leak coming from?

[Alex Hayley]

I did find that the gear selector shaft seal had not been replaced when the transmission was rebuilt. Real pain to spend a bunch of money on having a transmission rebuilt and the rebuilder does not even bother to replace that seal.

[70c10]

I'm having the same issue and taking my truck tomorrow to a transmission shop owned by a friend of a friend. I think mine is leaking from the gear selector seal also. I'm not sure but I think a special tool is necessary to replace that seal.