My '02 f150 5.4L 4x4 is acting up. Need help. It's shuddering or missing at 45 MPH or greater. Some reliable mechanic friends thought ignition coils or the torque convertor. This problem isn't throwing a code. Thoughts?

 

My 4.6 was doig the exact same. Try changing your transmission filter and fluid. My had 130k with the original filter and it was blocked to where it couldnt get enough fluid and was causing a shudder above 45

 

I have all ready changed the fluid and filter. I am also running 325/60/20. Think maybe that has changed the shift points. Bought the truck with tires all ready on truck.

 

My dad suggested the flex plate. It may have loose bolts or a crack. Guess not many has really had this issue to point me in the right direction.

 

Its a coil