This doesn't happen everytime I drive my 96 F-150, but eventually if I drive it long enough, the OD light will start blinking. This then causes the truck to shift extremely hard. If I shut the truck off and turn it back on after about a minute, it will stop blinking and it will go back to shifting normally.

I took it to my mechanic and he could not find anything wrong. I am hoping someone here will be able to shed light on this problem.

Thanks,
George

 

Your 96 should be OBDII. Your mechanic should be able to pull any codes for the flashing OD if he has the right code reader.

 

Your transmission is malfunctioing in some way. The blinking light is the Transmission Control Indication Lamp. If it's blinking, then a sensor has picked up on an error.

The codes can only be read by a specific scanner. An OBD-II scanner will not pick up any Ford Transmission codes, so you'll need to find another mechanic or take it to a dealer.

If it happens after you've been driving for awhile, I'd suspect the torque converter is slipping and setting a code for excessive heat. The transmission then goes into "limp mode" which shortens the duration of the shift to reduce heat. That's why it shifts so hard.

If the light blinks, there is a code stored. You just need the right scanner to retrieve it.

 

Thanks for the replies. I am in the middle of a move, and when I get to my new home, I will have it looked at again.

George