I have isolated the source of the leak to the right rear corner of the pan
(as seated in the driver seat). 'Have "diapered" all case penetrations to
insure that no ATF is coming from them. 'Have tried many different pan
gaskets over the years (and gasket sealants) but none completely stops the
leak. The gasket that appears to work the best is a NAPA # 14525. Emery
Stora reports using this gasket with good success. I installed that gasket
during the last service about 6K miles ago.

The NAPA gasket controls the leakage to about 1/2 pint (measured from a drip
pan) over several months of non-use.

There is no leakage when traveling (as observed from no blow-back onto a
clean, oil-free underbody).

There does not appear to be a problem with the integrity of the
transmission case or pan at the leak location.

I have been unable to convincingly rule out the chain cover as the source of
(or contributor to) the leak. If mine is leaking, the source would be from
just above the pan/case interface location stated above.

Thoughts on proving(or disproving) the chain cover as the source of the
leak?

Also, thoughts on why the pan still leaks (if not from the chain cover)
despite my attempts with a variety of gaskets (and sealants applied to the
gaskets) to stop it.




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I have isolated the source of the leak to the right rear corner of the pan (as seated in the driver seat). 'Have "diapered" all case penetrations to insure that no ATF is coming from them. 'Have tried many different pan gaskets over the years (and gasket sealants) but none completely stops the leak. The gasket that appears to work the best is a NAPA # 14525. Emery Stora reports using this gasket with good success. I installed that gasket during the last service about 6K miles ago.

The NAPA gasket controls the leakage to about 1/2 pint (measured from a drip pan) over several months of non-use.

There is no leakage when traveling (as observed from no blow-back onto a clean, oil-free underbody).

There does not appear to be a problem with the integrity of the transmission case or pan at the leak location.

I have been unable to convincingly rule out the chain cover as the source of (or contributor to) the leak. If mine is leaking, the source would be from just above the pan/case interface location stated above.

Thoughts on proving(or disproving) the chain cover as the source of the leak?

Also, thoughts on why the pan still leaks (if not from the chain cover) despite my attempts with a variety of gaskets (and sealants applied to the gaskets) to stop it.

my memory from reading here, and what I believe my own coach suffers from:

torque converter leak down. from my understanding, When running, fluid is in torque converter, no leak. When you stop, and park it, the converter leaks down and over fills the pan, causing some leaking out the pan gasket, cover or who knows??? Also why it is recommended to check/deal with the fluid level after the coach is warm and has been driven, then you have the accurate "underway" level of transmission fluid in the pan.

I have never seen mine drip a drop of ATF going down the road or running. But evidence of underside of transmission and the concrete where I park the coach, it leaks when parked. I attribute it to the converter draining down. Not thinking if I change any gaskets it will really quit.