I got a 96 f150 ext cab 302 auto 2wd.. I have a bad vibration around 45 mph . It is slight at lower speeds and at 65 cant really feel it. It feels like it is from the rear or centre of truck. I replaced rear shaft u joints and centre Carrier bearing. I did not replace the very front u Joint by tranny because it felt tight. I also rotated tires and vibration stayed the same. It just started after I had it aligned 2 weeks ago, I really cant see that having anything to do with it but what you think... Any help appreciated I just do not have a clue I tried everything I could think of.....

 

A improper alignment might do it, however it could be unbalanced tire/wheels. You may want to check the tires for abnormal wear like swelling or bulges. I got a great deal on my f-150 because the owner was fed up and convinced that the front end needed major work. The truck would shake at low speeds then clear up. I took it to a shop and they pointed out the front passenger tire was badly worn. I bought the truck at a steal and put new tires on it. Problem solved. Anyway I hope this helps, good luck.

 

Thank you I will check them very close tomarrow, I am done for the night been messing with it most of the day.... When I am going 45 to 50 and I put the truck in neutral the vibration seems to lesson quite a bit...

 

Anybody..........??