Stop leaking

[Purepony]

Summit has a really cool gasket I can’t remember what it’s called as far as like the brand but it’s a black rubber thick gasket similar to the ones they use on the newer cars because the center of the gasket inside is steel. I used it on my 904 and it wored real well it was like $40 but it was worth it

 

[Mackman]

I had a 727 pan that I couldn’t stop leaking. Tried cork and rubber gaskets and even tried copper coat. It seemed that the gasket was pushing out from under the corner of the pan in one spot. The cover didn’t seem to have enough contact area with the trans. surface. I bought a cast aluminum cover from Summit, end of problem.

 

[66Satellite47]

I've built at least 25 of my own 727's, with the DC deep steel pan. Never had a leak issue. I mostly used the FelPro gasket, semi rubber. The only cork I tried was not good. Don't over torque the pan bolts.

 

[1963JAM]

This number covers the 727 based units. 46rh/re, 47rh/re, 48re. Can be used from 62 on. There is also one for the 904 based unit, think its 4295875ac, but you need to check. Covers 904, 998, 999, 42rh/re, 44re. One thing thought on these two gaskets and very important. Per the TSB that announced these new gaskets, came out in late 90's/early 2000, there is a corresponding pan bolt that needs to be used with them because the gasket is a little thicker and the new bolt is like two threads longer. If you use the standard bolt, you can strip out the bolt holes in the trans case since there may not be enough thread engagement. I don't remember the bolt number, you'll need to contact a dealer to get the number or bolts.
Cork gaskets are a well known leaker of fluids. The mothership used to use them then phased them out to the new unit to stop the incontinence issue. The newer RWD transmissions use a special RTV sealer on the pan instead of gaskets. Same goes on the FWD units but that started not long after they came out. The correct sealer is fluid specific for ATF usage. They used to have to use a small bottle of an additive that kept the ATF from foaming on the FWD cars because of the reaction between the sealer and the fluid but that stopped when the new sealer came out. So if you decide to use sealer only or a light smear of it on the gasket, make sure it's compatible with ATF.

Very good intel ckessel. I appreciate the insight on the gasket and ATF specific sealer. I’ve had my fill of the smell of the tranny drip on the exhaust. Though the undercarriage is well oiled and rust resisatant.
Thanks again

 

[ckessel]

You are welcome. When I worked at the dealers, I checked out the info on every TSB[ technical service bulletin] and recall notice that came through. It's amazing how much of this info could be used for the older rides. Unlike most of my counterparts in the department, I checked it all out. All of the info was kept in binders for reference when needed. Being on the front lines was very informative.

 

[66Satellite47]

I'm sure your profession experience far exceeds mine. But my 35+ years experience building 727's tells me the Felpro gasket properly torqued with a good pan will not leak. Don't know what the service bulletin can tell you.