Re: E40D help...
My first thought is that what you described is impossible. You have a four speed transmission, not a five speed. So it can't shift to fifth gear, there are only four gears.
You might be seeing the torque converter locking and unlocking. Or it may be shifting from fourth to third gear. What happens if you press the OD
OFF button to keep it from shifting to fourth gear? Then if it does it we know that the problem is the torque converter locking and unlocking.
Former Ford Automatic Transmission Engineer
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