Persistent Transmission Pan Leak

[gsbarry]

I have a pesky transmission pan leak that I'm having trouble solving. It's a very slow leak when sitting in driveway, on an incline, out the back of the pan gasket. Initially had a cork gasket in place, thinking that was a bad gasket, I replaced with felpro (black paper-like gasket). Still leaking. Thought possibly pan was slightly warped, so replaced with new aftermarket pan (Dorman), and felpro gasket again. Still leaking...

Torqued bolts in sequence (cross-ways starting from middle) to spec (~110 inch-lbs) with tq wrench every time.

Any suggestions on next steps? Thoughts that come to mind are: don't park on an incline (not a great option), the trans case is warped (even worse), replace again with some other kind of gasket (not sure what), maybe add some kind of sealant, or make a mess and waste time with hi-temp RTV. This is on a 5R55E, but doubt that matters.

 

[jmvb]

x2

 

[poker4me007]

Are you using any sealant on the gasket ? If not try puting a thin layer (I like the blue rtv) over both mating surface's with the gasket...
https://www.permatex.com/products/g...-blue-multipurpose-rtv-silicone-gasket-maker/

 

[Mbrooks420]

I would get a rubber reusable style pan gasket, and I'd avoid dorman products unless you absolutely have to.

 

[koda2000]

The pan is probably warped. Remove it and take a straight edge to it using a flashlight and see if you see any light shining through the pan edge and the straight edge.

I use Wix trans filters and they come with a rubber gasket. Their instructions say to apply a thing coating of grease to the gasket before installation. I've never had a leak.

Question:
When you dropped trans pan the first time did it have the OE pan gasket with the steel slugs to prevent over-tightening? If not it's quite possible that someone over tightened the bolts and warped the pan.

In the past when I've had trans pan leaks that I could get to stop I've replaced the steel pan with a cast aluminum pan.

 

[SWIGIN]

The best gaskets for pans and valve covers are the stock type that are steel with some rubber beads on both sides. My 94 Mustang still has the factory gaskets and they have been reused maybe a dozen times in it's 190,000 miles with no leaks.

 

[koda2000]

I find Felpro Perma-Dry gaskets work pretty well. I've used their one-piece SBC oil pan gaskets and they even come with these plastic screw-in things that allow you to hold the gasket in place while you reinstall the oil pan and they also had anti-crush sleeves.

 

[SWIGIN]

I have used them as well, they are a stock type gasket like I described above.

Any metal gasket with rubber ribs will seal and not warp the pan since the bolts cant sink into it.

 

[gsbarry]

Thanks for the input guys. Been a few months since I've had time to address this. I found an aftermarket rubber clad steel type gasket from global transmission parts (my trans is a 5r55e) for $25 shipped. They seem to be the only company making this style of gasket for the 5r55 series. Hopefully this does the trick. Just want to reiterate I have a new pan that has only been properly torqued (sequence and torque values), so I'm fairly certain at this point the problem is not a warped pan.

What is the consensus on applying a bit of grease to the gasket during installation? If so, is a generic wheel bearing grease the way to go, or something else? Also saw a mention of adding a bit of permatex sealant in place of the grease.... I've always been told that gaskets (and gasket surfaces) should be clean and dry with zero sealants added, but the conventional wisdom may be wrong in this case.

 

[koda2000]

My WIX gasket (which is rubber or vinyl?) recommended applying grease to the gasket before installation. I did and have not the slightest hint of a leak. I imagine the grease helps the gasket to move to where it needs to be during installation. I'd do it. Don't see how it could hurt.

Any kind of grease should be fine. I used wheel bearing grease I'm sure.

 

[jmvb]

Anyone know the tranny pan torque and screw order?

 

[jmvb]

Thank you Mbrooks420
Yes, for the 5R55

And it is no special screw order?

 

[Mbrooks420]

Thank you Mbrooks420
Yes, for the 5R55

And it is no special screw order?

There probably is. Looking for it.

 

[koda2000]

I always run the bolts down to snug using a criss-cross pattern using a 1/4" ratchet, then tighten them down the same way. It's hard to over-tighten them using just a 1/4" ratchet (and only using one hand). I don't bother with the torque spec on something like a trans pan bolt. I go back and check them the next time I'm under the truck, but I haven't had any leaks.

The OE Ford trans pan gasket had little metal puck things in the trans pan gasket to prevent warping the pan. I suppose it's reusable, but I just used the gasket that came with the WIX filter I bought, greased it as the directions said before installing. I also installed a drain plug. The pan hasn't leaked/seeped a drop in about 12 months now.