Anyone have any recommendations on transmission pan gaskets? This is now my fourth time in less than a year to replace the leaking pan gasket. Not sure what the deal is, I do not see any warpage on the pan, been using OEM gaskets from mopar and it does not seem to help. I need this fluid leakage to permanently stop.

Thanks,

 

I think when Durangos survive the 20 year mark, all kinds of stuff starts to fail. replaced just about all the failed components on this rig. Only the main engine and alternator and AC compressor is what is left that came on the truck in 2000. Most other external components failed on me a couple years ago. So given my 230k miles, it's not that bad other than going to my 3rd transmission rebuild and now my broken front differential hub due to the missing mount. But tranny is the one that has been my achilles heel on this truck. 2nd tranny build by fastman's transmission guy lasted 100k miles before it went. Only the 5.9 engine seems running like it was new. no problems so far..

 

Steel wool the surfaces and use some oil resistant Permatex black, 1/4" bead on both sides of the gasket. Barely finger tighten the bolts, wait about an hour, then torque them all the way. Make sure you're tightening in a criss-cross sequence, starting with the innermost bolts and going along in increments. You want to even it out gradually to full torque.

 

When you have the pan off, lay it on a flat surface, to make sure it isn't warped. Also, if the bolt holes are dimpled, flatten 'em out. The Viton gaskets *usually* are pretty forgiving..... the cork fellers just suck.

 

DON'T use RTV at least not 1/4" bead on both sides like has been suggested / that gasket should seal with no additional RTV. I have 3 Dakotas/Durango with factory style pan gaskets, no leaks on any of them. I just had the trans out of the 99 Dakota for a bad front band, the last idiot that was inside the trans (before my ownership) used the cork gasket that came with the filter and about a tube and 1/2 of blue RTV besides.... What a freaking idiot. If you want to smear a very light coating with your finger probably wont hurt, but that excess that squeezes out when you go nuts with it has to go somewhere..... and I have seen wads of RTV inside a trans from having done just this, in some crazy places.... especially using a factory gasket.

are you completely SURE the leak is the pan gasket? There are a few locations just above that area that can leak and "look like" that is where it is coming from....
Neutral switch, linkage pass thru on driver side, electrical pass thru right behind that on driver side, dipstick tube seal (or rotted dipstick tube) on passenger side or even the pump seal behind the converter..... check those out. and last thought.. You have all the bolts in the pan? Any stripped threads?
On my son's 727 in an older truck, he took the trans out and took it in for a "bench rebuild"...…. and knew there were a few holes in the pan rail that needed heli coils... the shop said "Oh yeah no problem"..... Well yeah it was a problem that got pushed onto me. On 727s, 904s, 42 RH/RE, 44 RH/RE, 46-47 RH/RE the pan bolts were SAE thread from new, a 5/16-18. The idiots at the trans place had a hodge podge of std and metric bolts in the pan..... My son didn't notice this when he reinstalled the trans but when it continued to leak, Ol Dad (me) had to drop the pan and fix it right. When it had gone to the trans shop it needed 2-3 holes Heli coiled. That was it.
besides scrounging for some of the right bolts for the job I wound up having to heli coil like 7 holes in the trans case...…. what idiots at this trans place cant say Id recommend anyone to use their services in the future.... I used to use them when I had a trans to rebuild that was a GM or Ford for someone else with me doing the R&R.... but now I aint so sure.

 

"Should," but it's not, hence my suggestion. This is not a normal situation, else OP wouldn't have posted. If the surfaces are uneven, the RTV will aid in filling the spaces but it's important that he wait a while till it thickens, before torquing down, so it doesn't squish out the sides. That's how you end up with a mess.

And yeah, cork sucks.

 

Hey brother Kensai, it may be time for a new pan.

However, I would take it off and place it on a nice flat surface. Take a nice flat wide block of wood that will set between the lip and the rise and smack the wood with a hammer to flatten the sealing surface it all the way around, especially around the bolt holes as previously stated. Clean it all really good with brake cleaner. Most likely that will fix the issue. Now get some RTV Permatex Ultra Black and pit a really thin coat on it and rub your finger on it all over the lip so its nice, flat and thin. (The object here is to seal any weep hole caused by possible gouging that could possibly be there). If the bolt holes are found too warped it may be too late to fix.

Usually the OEM pan gasket fins "should" seal especially when you very lightly moisten with a grease before install, however if there is a gouge it will weep, and that were the tiny bit of RTV comes into play. Torque bolt area pan warp is usually not a problem if there is metal inlays around the bolts holes in the gasket which allows the torque to go onto it instead of warping the pan into the gasket face.

Next replace your filter, adjust your (rear band if needed (most aren't)) then clean and put a tiny flat amount of the RTV on the trans sealing surface and button it up. Torque sequence should be followed and just a bit of torque on them (about 5inch). Wait about a half hour then finish torque them down in sequence. Wait 24 hours then fill up with ATF+4 Fully Synthetic. Finally, adjust the front band if necessary on the side.

A trick to keep your pan bolts from loosening is to clean out the threads on both sides, put a little RTV on the threaded bolt end before install. As it dries it will keep them from backing out.

Good luck my friend!