i have a 97 f150 4.6 on 35's. the tranny is calibrated for the tires. at cruising speed around 55+ every now and then the overdrive off light starts to blink. it was happening before the 35's were installed. also at 70-80 using cruise control the tranny constantly downshifts and upshifts followed by the overdrive off light blinking. when i shut the truck off and turn it back on the light stops. what could this be? maybee fluid or something, i dont know. i plan on installing a shift kit this weekend to put less strain on the tranny and hoping by some miracle, maybee new fluid/filter/flow will stop the stupid light. by the way it has 131,000 miles on it.

 

You need an OBDII scan tool that can read Ford specific codes. Without that nobody knows what's making the light flash.