has anyone expirienced a drivetrain clunk or jerk at around 50-60mph? under light load there is a jerk/clunk coming from the drive train. i believe it to be a pinion gear issue but not sure. i was wondering if anyone had this issue and what the fix was. i have 2004 supercab with a stepside bed, 5.4L

 

I've had it since I got my truck in 04. Seems to be more of annoyance than an actual problem.

 

can't remember if this was for stock applications or some of the first edge tunes but there was a problem with the torque converter locking and unlocking. This would seem more like a constant shake or jerk. if it was a factory problem your pcm needs to be reflashed at a dealer.

another possibility is the truck is searching between 3rd and overdrive. this might also be corrected by a reflash of the pcm.

both of these problems seem like a constant shake or jerk though. if this is what you are feeling you can be drastically shortening transmission life.

 

if i drive steady at 50-55 then it is a constant jerking. most of the time though its me getting to 50 then stepping on the throttle then feeling the clunk.