2003 F150 4.6L 4x4 Auto
Had alignment done, transmission flushed/filter replace, re-balanced tires. Still getting vibration at ~ 95 km/hr, or 50 mph. No heat on brakes or rims, moderate heat on rear differential, no heat on front differential, but noticed considerable heat on transfer case. No pull noticeable on front end. Notice more grab/jump on tight turns at low speed (2wd mode) than on my 98 F150 4x4 5 spd manual. Any ideas appreciated.

 

Check U joints, Do the tires have any Bumps in them? Shocks? Loose Drive shaft?

 

vibration at 50 mph...check ujoints like mike said...or your tires could be out of balance.

 

Mine started having a random vibration at around 110k miles. I checked in the wheel well and the sway bars links on both sides of my truck were snapped in half(rusted I believe). Replaced them the next day and the vibrations stopped.

 

Appears to have been front drive shaft, rear u-joint. Was starting to tick/knock as well (under driver floorboard) at low speeds as well. Replaced for $175 at independent shop, now all appears good after one short road test. Dealer charged me an hour to look at without any finding...

 

Front drive shaft should not be turning, unless it's in 4 wheel drive.

 

I thought I saw that comment before, but not sure how to test it? My 98 F150 4x4 S/C 5spd front drive shaft turned, I noticed when I did my clutch last year, as I needed to hold/brake wheels while removing shaft. I did not have any vibration issues with that truck.