im doing this for my dad, he has an 99 mustang conv. ever since he got his corvette toy, he has let the mustang take a slight shit, but since he got his tax returns he asked me to work on it since i take auto repair, first i thought it was the transmission, so i did a tune up since i heard spark plugs could mess with it, well the transmission problem went away, since i rarely ever drive the car he doesnt really tell me whats going on with it until he got the tax returns, anyways around 55mph and up it starts vibrating badly, so i changed out the wheel bearings/hub assembly and since i was down there i also shaved 3 rotors and replaced one with new pads all around, on the way home from school it started vibrating again but not as bad it starts at 55mph and u dont really notice it once im going 70, so i have no clue, any idea what else i should be looking into? i have new ball joints standing by in case that could be part of problem, im bringing it back into school tomorrow and it would be nice to have an idea where to look, thanks and sorry for this long message.

 

A tire.

 

they were just rotated but the vibration is still in the front like before, but i will get them balanced at school and see how that works.

 

Bent drive shaft?

 

idk about that but i'll check to, he doesnt beat on it so have no idea how that would happen anyways

 

Check the tires and tie rods. Does it shake more in the steering wheel, pedal, or your seat?

 

more in the steering wheel i dont feel it in the pedal or seat.

 

definitely check the tires and tie rods

 

alright, thank you, i'll post what i find later on.

 

3 tires are shit, 2 have camber wear and one has an air bubble in the side wall, so gonna get a set of tires and do an alignment and go from there