Engine/Transmission (1994 - 1998) transmission slipping out of O.D

[MSnow]

98. 5 2500 4 speed auto. Slips in and out of overdrive. between 50 and 55 mph. Happened once before and the transmission shop said it was a wiring harness. they fixed it. 8,000 miles later same problem. Before I take it to the shop,any ideas why it's happening again. (normal everyday driving no off-road or heavy hauling)

 

[Fordiesel69]

Possible TPS is dirty. I don;t know how you test it but here is a thread:



TPS testing and adjustment