Oil pan - Use gasket or Hi Temp Red RTV

[thatguy]

I had the auto transmission (2500 Dodge Ram Cummins - 47RE) serviced about a year ago and had the repair shop install a new OEM transmission gasket (which i was thinking was rubber-ish)..

It appears that the pan is now leaking so I may need to drop the pan and do something with the gasket so it stops (after I check to make sure the bolts are not loose)..

Do you recommend using a new gasket OR making my own gasket with Permatex High Temp Red RTV gasket maker?

Specs call for 13/ft-lbs for the gasket but the RTV says something like - outline pan edge and around the bolt holes, let it set up, tighten until it oozes out.. Wait an hour and then tighten another 1/2 to 3/4 turn..

I have never used RVT before and not so sure about the bolts not being very tight - which method would least likely leak?

Brian

[flusher]

I had the auto transmission (2500 Dodge Ram Cummins - 47RE) serviced about a year ago and had the repair shop install a new OEM transmission gasket (which i was thinking was rubber-ish)..

It appears that the pan is now leaking so I may need to drop the pan and do something with the gasket so it stops (after I check to make sure the bolts are not loose)..

Do you recommend using a new gasket OR making my own gasket with Permatex High Temp Red RTV gasket maker?

Specs call for 13/ft-lbs for the gasket but the RTV says something like - outline pan edge and around the bolt holes, let it set up, tighten until it oozes out.. Wait an hour and then tighten another 1/2 to 3/4 turn..

I have never used RVT before and not so sure about the bolts not being very tight - which method would least likely leak?

Brian

Or cut a new paper gasket from gasket stock (McMaster Carr) and use Permatex gasket seal (the tacky type). I just made new axle gaskets for the old 1951 Minneapolis Moline BF tractor that I'm restoring

[brokenot]

Install a gasket like there originally was, and torque the bolts to spec.

I've torn down and rebuilt quite a few automatics because RTV was used to either glue a pan gasket in place....or replace one altogether. If used very sparingly to glue a gasket in place and then left to set up, you'll be okay.

You do not want to glob a whole tube on and then button everything back up immediately, because some of it will ooze out inside the pan and muck up the components inside once it starts floating around.







(Now where are those pictures I took a few years ago of a valve body contaminated with wee bits of rogue RTV?......)

[Gale Hawkins]

Have you tried tighting them? I was under the MH and saw a few seeps and was able to snug them all some with a 1/4" short rachet so I would not over tighten them.
Too tight can distort thin steel pans.

[LD1]

Install a gasket like there originally was, and torque the bolts to spec.

I've torn down and rebuilt quite a few automatics because RTV was used to either glue a pan gasket in place....or replace one altogether. If used very sparingly to glue a gasket in place and then left to set up, you'll be okay.

You do not want to glob a whole tube on and then button everything back up immediately, because some of it will ooze out inside the pan and muck up the components inside once it starts floating around.

I agree. RTV is a no no on trany pans. The RTV can cause havoc with the very small passages and valves inside.

I have used it before but the ONLY way I would reccomend it is if you are using a cork gasket. Smear a thin layer on both sides and let it set up BEFORE you install it. If you are using a rubber gasket it should not be needed.

I would not use a gasket made of gasket paper either UNLESS it has a cast aluminum pan. If it is a stamped steel pan, you will have a very hard time getting a paper gasket to seal, even with the RTV.

[Reg]

I don't know the particular trans, but IF it is aluminum and IF the trans shop overtorqued some of the bolts that COULD be the reason for the leak - in which case your options are limited.

If not (and/or not) you should be good with an OEM gasket, I think MOST of them these days are reusable, they don't pack down, they spring right back each time you use them - "elastic" I guess.
.

[timswi]

RTV doesn't work as an automotive gasket when used alone, as a quick side of the road repair maybe, but it will begin leaking again in short order...Spring for the gasket. Sometimes you can find a gasket that will help with slight out of kilter pans. They used to have these anyway.

As others have said, RTV on cork is fine as long as you let it set up so it won't squirt into the trans. Rubber is supposed to be installed as is.

[Diamondpilot]

I agree with the others and get a gasket.

Quick trick of the trade. Take the gasket out and lay it flat with books on top of it a day prior to install. That is only possible 1 time out of 1000 so what I do is lay it on the pan and tire it in position in all 4 corners with sewing thread though the nearest bolt hole. Now install all the other bolts finger tight and then use a pair of snips to cut out the thread and remove. Now you can install the 4 remaining bolts and torque.

Chris

[brokenot]

RTV doesn't work as an automotive gasket when used alone

Sure it does....it's used in place of traditional gaskets in lots of applications. I just replaced the intake manifold gasket on my Ranger, for example. The replacement gasket doesn't even include the rubber gasket inserts that seal up the front and rear manifold-to-block gap. A tube of RTV is included and a bead is run along the top of the block after the block and manifold are cleaned and dried. As the manifold is set in place and torqued down, the excess oozes out. If there were no RTV in there, the open gap between the manifold and block would be about 1/8", and there would be oil leaks aplenty.

RTV is used in many such applications....transmission pans just aren't usually one of them. And for good reason.

[yankeerider]

I had the auto transmission (2500 Dodge Ram Cummins - 47RE) serviced about a year ago and had the repair shop install a new OEM transmission gasket (which i was thinking was rubber-ish)..

It appears that the pan is now leaking so I may need to drop the pan and do something with the gasket so it stops (after I check to make sure the bolts are not loose)..
....

Brian

Is the vehicle driven daily? Reason I raise this question is I have experienience with a different auto that had a poorly seated anti-drainback valve. (Keeps the torque converter from draining into the tranny when not running, which can overflow the trans, causing it to leal through vents and other penetrations.)

At first inspection it looked like the pan gasket, but after changing out several times I realized that was not the problem. A vehicle driven daily or close to that will not exhibit such a problem, but one that sits for a week (or more) at time will.