Alright..I have a '85 pick-up 4WD of course...it's got the 22r-e motor with a four speed w/ over-drive automatic trans. Not sure the model number...on-line says it's an A340F and Chilton says it's an A-43D. At normal acceleration, it shifts through 1st and 2nd fine, but it only goes to 3rd for about a sec and then straight into o/d. So i am only going about 30mph when it puts me into o/d and it bogs the engine down. Then if I let off the gas just a bit, it will shift it back down to 3rd. I have checked the fluid and it is fine. Don't know much more about it. Anything would help. Thanks for your time.......Richey

 

I'm not sure on your truck, but a t-100 I helped swap motors in had shift cable that hooked to the throttle body. If you have done any repairs in that area, it might have got out of adjustment. you might also check where the cable goes into the trans. the cable affects the shifting but it may not cause your problem.