Trying to help a friend:
"Anyone know of a good transmission shop in East Tennessee? I followed advice and took it to Clark Power in Knoxville, but they don't have anyone who knows anything about an Allison HT transmission. They want me to take it to their Antioch location, but I'd sure like to find someone in my neck of the woods...."
Check to see if Transtar has a location in Knoxville they work on HT model Allison's
I see they do. I passed it on, thanks!
It maybe just parts only at that location but they will know of a shop close