Oil pan - Use gasket or Hi Temp Red RTV

[crazyal]

What type of gasket did it have? Was it a thin one or thick like a valve cover gasket? Is the pan sheet metal pressed into shape? Often I see sheet metal pans where the holes for the bolts get bent because the bolts were over torqued. It usually happens with the thicker gaskets. Once it happens your best option is to replace the pan or find stiffeners like they use with some valve covers to put pressure in between the holes.

If you do use RTV, clean the surfaces well and then let it dry before adding any oil, at least over night. Secondly it's better to use a thin layer of RTV on a gasket than a thicker layer all by itself as you'll have less chance of it squishing out inside the pan and flaking off only to get caught in an oil passage.

 

[jonyyuma]

Steel pans can have the dimples taken out, from over-torque, if you are careful. First I would insure the bolts were properly tightened from past repairs? Check to see if the pan really is the culprit? I have used rtv very sparingly to seal a gasket to the pan, or Indian sealer, or Permatex. Chevrolet did thousands of them for years,with rtv, no gaskets involved... but sloppy ness can cause major failures.>

 

[Diamondpilot]

RTV and the only sealant is used all the time but I would go back with a gasket if available. Most every rear diff I have had apart and lawn mower trannys also only use RTV for a gasket.

Chris

 

[Car Doc]

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

A cork/rubber gasket is the best type gasket because the cork is just a better sealer and after oil gets near it the rubber swells up and helps keep the gasket under tension.

With that said RTV is a better sealer on a tin pan. Just pound out the bolt holes backwards slightly with a tap hammer so the hole pulls in to the case. Clean the surfaces with brake clean real good and try to make sure the trany is done dripping when you do this add a light even smear RTV on the case and the biggest portion on the pan (like sticking 2 pieces of tape together) but remember you dont have to put more than 1/8" thick and just tighten it about 1/4" ratchet tight and leave it overnight if at all possible. hth also I use hi temp gray or black not the super high temp red stuff for what that is worth....

 

[orezok]

I would go strictly by what the manufacturer recommends, not the counter man at xyz auto parts or this is the way we always did it. Attached is the Factory service manual for current model Dodge truck since about 2002.

The 47RE is the same basic transmission.

 

[jonyyuma]

Hey Car Doc, I also use brake clean for those areas, plus you can rinse the pan. No chance of fiber or fuzz from wiping.The hardest part is cleaning the magnet. Matter-of-fact the last couple times draining pan did not even need to change the cork gasket..

 

[Car Doc]

Hey Car Doc, I also use brake clean for those areas, plus you can rinse the pan. No chance of fiber or fuzz from wiping.The hardest part is cleaning the magnet. Matter-of-fact the last couple times draining pan did not even need to change the cork gasket..

There ya go! :thumbsup:

 

[thatguy]

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.

Interesting - I do not drive it daily, only a few times a week (about 7k miles/yr).. So this may be the problem - what am i looking for in trying to see if it is the anti-drainback valve?

Brian

 

[Car Doc]

Lots of trannys are sealed from the factory with RTV. Toyota's Aisin Warner units are one example.

Since I work on Toyota's for a living I see lots of dry leak free trannys. :thumbsup:

 

[Car Doc]

The factory offers a nice clean environment with a transmission that has never seen fluid and is probably inverted when the pan is installed. Crawling under a dirty old truck, scraping RTV or gasket material, and the steady drip, drip, drip is a little different.

Yeah aint that the truth though! I do this stuff every day and wonder how they expect us to make a living at it working upside down and twisted around and sideways!