Have a new F150, FTX, 2WD, 4.6L V8, Auto. Had vibration in steering wheel at 40 - 45 mph. Dealer installed new pinion/gear/, shims and dampning kit to rear. Seemed to help, but still have mild vibration in steering wheel between 45 - 60mph. This seems to only happen after truck runs a bit and things warm up. Not tires as it stops when I let off the gas. Any suggestions?

 

Sounds like something in the power steering system...

 

get your wheels re-balanced

 

Kinda mis-read the post...I agree, 1st ensure the wheels are balanced properly then check to see if the tires are "out-of-round" when they get up to operating temperature. You may also have a weak spot forming in the tires that is showing itself at those particluar speeds when the tires are warm. Assuming that all of this checks out ok, then I would look into the power steering system (possible check-valve problem).

 

last time i talked to someone about a vibration in the fron tires the tires had a broken belt in both of them.

 

your drive shaft may need to be balanced. or maybe bad u-joints, i only say this b-cuz you said it stops when you slow down, just my 2 cents