Re: leaking th400
 

Definitely run the fluid level at the add mark.
Another area I've had issues with lately is the shift shaft seal .
It appears the newer seals are not as tight on the shaft as ones I had from old kits.
My solution has been to machine a groove in the shift shaft and install an o ring .

Re: leaking th400
 

That's interesting. I was just laying under my car last night after installing the engine and trans (glide) over the weekend, and noticed some fluid on the end of the shift shaft which I've not noticed before.

Re: leaking th400
 

Just a quick heads up.....

Don't use RTV sealer on gaskets because it acts as a lubricant and allows the gasket to push out. Just completely clean both surfaces and use brake clean to remove any residual oil and use the gasket only...

OR

You can do like GM did, which was do not use a gasket at all. You can use anaerobic sealer or RTV, with the surfaces clean and bone dry put it together. Woks on engines and transmissions, just make sure it is allowed to dry and set up before exposing it to oil. This isn't for a race engine or transmission which is constantly being worked on, but it works great on a stock rebuild for the street.....

Your results may vary....

Re: leaking th400
 

You really don't want to use any RTV sealants that will come in contact with ATF . Most ATF has an anti-foaming additive and RTV will destroy that additive . Most manufacturers that seal structures ( like case halves) will use a Poly-Acrylic sealer. PA has no effect on ATF.

Re: leaking th400
 

Just a heads up.....

GM used that Orange RTV on TH700-4R transmissions and HT4100 engines for years....The surface has to dry and the RTV given time to completely set up.....

It's your choice...

Just sayin'

Re: leaking th400
 

That RTV ended quickly after we in Engineering discovered the problems with the RTV's effect on the anti Foaming additives , and Off gassing that would rust internal transmission parts . Cadillac may not have had those problems with their engines , but most anything that was designed after GM's experience with "orange" RTV was either done with a gasket or the PA material I mentioned before .

Re: leaking th400
 

ok tks everyone! milodon unit installed, nice piece.... . marked the gasket/panrail installed height on dipstick. i have an additionail .125'' more capisity before level would reach the modulator valve bore. (which i believe is the seepage) sooo where does the operating level go? above or below the pan rail & gasket height? new fiber gasket to be install dry.

Re: leaking th400
 

The best / sure way to check dipstick height is to get a stock dipstick tube and stick. Insert in the trans and with the pan off measure in relationship to the pan rail. Transfer this known height to your new / aftermarket stick. This way you can't be wrong.

Re: leaking th400
 

The add one pint level is about 1 1/4” from the tip of the dipstick on a stock piece.You can figure about another 1/2” to the full mark.Although it’s permissible I don’t usually run the oil level right at the full mark.Make sure you’re checking the level with the engine running/trans in park or neutral. With the engine off and the trans sitting the fluid level may well be above the full mark.
I would try the oil level right where you have it.Again, road test and heat cycle the trans.Then check the level.If the level when hot is above the .125 you measured,lower the level until it is even or slightly below.