I have a 2005 F150 SuperCrew shortbed with the 4.6 L V8 with 66,000 miles on it. Between 45 and 50 mph the truck has a slight bounce (resonance) in the rear. It is not really bad, just annoying. The shocks seem fine as the truck handles very well. I don't want to replace them and still have the same problem. I have seen this before in other trucks, usually because they are lowered. Mine is completely stock. Thanks........

 

need new wheel weights

 

Nope, not wheel weights, under certain conditions the vehicle will have shake. There is a service fix for this. There is a frame damper that can be installed to minimize the bounce. Read through TSB 04-25-7. Sounds like its more this than tire/wheel imbalance

 

The bounce is in the rear and I think you are talking about a frame mounted steering damper..........

 

Check your driveshaft. Literally jack all 4 wheels off the ground, slip it into drive and watch it. Mine was bent without doing anyhting that would normally bend one. Weirdest damn thing I'd ever seen.