The e4od is junk. Itll cost four grand for an ok rebuilt or reman one for you to have the same problems. Wouldnt bother with a used one. The problems are endless from cracked flywheel, cooling issues, computer, on and on.
Im guessing its in a f250/350. Bit more of a process, but if youre keeping the truck look for a junk but complete zf 5spd truck with the same diesel, 7.3/6.9? Ya gotta swap over everything from the manual truck including the computer. Pedal assembly, clutch master, bellhousing back, etc. If you can swap an auto for an auto you can do it. If the truck is 4wd, youll need a 4wd donor truck. Theres plenty if good write ups on ford truck forums. Even a junk truck without the engine but complete otherwise.