Sorry for title....couldn't think of a good explantation for my issue. Over the last couple of trips pulling my horse trailer ( 16-17k +/-) or even empty when I put lite pressure on the throttle or if cresting a hill it's like the the truck starts bucking as if the throttle or govannor is bouncing back an forward. then as I start to pull again it smoothes out again. Only started this in the last couple of trips. Due for 5000 mil service in less than 2000 miles. any ideas? 2008 F-350 6.4L 27,300 miles on truck

 

Moved to the 6.4L Powerstroke Diesel forum.