At approx 35 and 50 it feels like it's shifting back and forth between gears. It does this on about two second intervals, down up...down up. When I'm going 50 I can turn the overdrive off and that takes care of it.
A couple of years ago I had the governor replaced by the local dealer under a extended warranty that I bought with the truck. It solved it then and I'm thinking it's the same problem but I don't have the warranty and don't want to have to through this every couple years. Thinking if it isn't to hard to do I'd like to convert it to a manual.