Shop, thats what I did. My 97Xcab LWB 4.6 auto started feeling like a railroad crossing from 3 to 4. I had Ford tell me it could be a faulty Torque Convertor. Could be a Tranny. They started out at 3600 without the Convertor. 500 more for that. Any gears that were trashed would add to that. I finally stopped the service man and said ,"Whoa, how much for a new Tranny from the plant." They are nuts. I ask a few people around town and found a Tranny shop that specialized in performance convertors, kits, rebuilds and speed products. He gave me the best price and the best job. Before I bragged, I have 12000 miles on it and no problems. Gave me the Mustang wide convertor. (my truck convertor was a problem with the 97) Installed the shift kit, amsoil and built it to pull my tractor without the worries. I have the same warranty as Ford, and the guy has a great reputation. I checked out his website and got a little extra deal too. I figure any guy who races Ford dually diesels, has got to know something about strong trannys. It pays to shop. Believe it or not, Ford had a 97 swb v8, auto on the used lot for 8000. Sure it had a few miles, but for the cost of their tranny rebuildk, I could have bought that truck.