Just bought a 93 with an E4OD in it. Owner says both engine and transmission that are in it have 150k miles (truck body has almost 300k).

The transmission is a little weird. If driven normally it will rev high in first gear before switching to second. It shifts to third fourth and OD fine. However, if you turn off the OD while in first gear (about where you would want it to shift) it shifts to second smoothly. Once it gets into third you can turn the OD back on and you're good to go.

Any ideas on where to start fixing this?