Okay, update time....
The trans is out of the hemtt, and down at the Allison shop in Tacoma. They disassembled it and had some surprising things to say about this transmission...
It is definitely not a hemtt tranny, or anything that came with a Detroit 8V92... It is from the mid 70's, has a Cummins torque converter and starter ring (surprised it even worked), a very incorrect valvebody, the wrong pan, etc, etc... The mystery of what this was for will probably remain a mystery, but we know that it failed because of mismatched valving and torqueconverter failure, not fluid.... It simply was not the transmission that should have been behind this engine... But on the bright side, they are going to be able to rebuild it into a very nice transmission that will shift crisper and function better then what it came stock with. Not to mention that it has an extra gear then stock, which is nice for that narrow 8v92 power range.
All for the bargain price of $8000.... Actually these guy are really cool to work with, and they are very interested in the project and are trying to save me money where they can and still build me a first-class transmission. They even are willing to travel the 100+ miles to supervise the install and provide technical support for the initial setup. So this, and the r/r costs, I'll be in it about $10K or so. It's pretty much all I have left on the budget for this truck for the year, but it has to be done.
On a side note, I consulted with the Allison Factory tech support folks, and obviously the builder here. They all told me that running anything but C4 ATF in this is a huge mistake. Allison doesn't okay 15w40, and the local shop won't warranty it. The history of the US Military using it had to do with fluid commonality and pressure on Allison to get the contract. They tell me the heat handling ability of the C4 ATF is just as capable as the 15-40 oil and oil will be to thick to function reliably in the colder weather.
Bottom line is this - I know some of you guys strongly recommend the 15w-40, but for what I am paying for this, I would be a fool to do anything except what the factory and the experts say to do. There are allison autos running in heavy-duty rigs all over the world on C4 ATF, and they seem to work.
I will be adding a second spin-on aux filter on the fluid return line from the cooler, to filter any particles that may be trapped in the cooler, also, by the way on Allison's recommendation.
Thanks for the Video!!!!!!!
