'98 F150 XL, 4.2L.
The truck was smooth as silk until I did some brake work. I just went through my brakes and ended up putting new rotors (China) and bearings.
Now when i get up to 55- 63 there is a very noticeable vibration and the front starts to shake. If I slow down or speed up it goes away, but at those speeds my truck does the shimmy shake. At first I thought the wheels may need balancing, but they were fine before I did the work. Could the rotors be out of balance? I noticed some notches on them like they were balanced. Any ideas? Thanks.

 

were the rotors on the the thin side?? u need to measure them to make sure they are still in spec. doublecheck your lug nuts, caliper pins.

 

they are thick. Brand new rotors.

 

possible your driveshat could be out of balance. that can make then whole truck shake at those speeds. check your entire front end as well. ball joints,tie rods., all linkages etc..

 

The rotors could be out of balance. Not sure if a tire shop could check that for you or not, but that would be my first guess for the vibration source if it was good beforehand.

 

Have warped three sets of rotors. They always appear to be fine when just looking at the rotors. It is a known problem on these F-150s, if you have a good dealership they should cover the replacement for free.

 

Thank you all for your help!