Long story short, my transmission start slipping in 5th gear. Took it in and the transmission shop and was told me my c2 clutch was bad and bad 4th and 5th gears. Bought a new suncoast transmission and still have the same slip in 5th after driving for 15-20 mins. Found out a rat had chewed a handful of wires under my fuse box. My truck has been at a one man diesel shop for 3 months and the he "hasn't had the time to look at it". I thinking about picking the truck back up and giving it a shot on my own. Where would yall start?? How would I diagnose the tcm or ecm??