Vibration diagnosis

[Sid_RallyX_82]

'91, B3, 5speed. I have a really bad vibration problem. It really becomes noticeable at 80 and above, but you can just get a hint of it at 60. As I got faster, it just gets worse. It shakes the whole car and it's shaking loose my dashboard. It fades in and out, alternating about every five seconds, like there are two frequencies lining up, then synchopating, then matching again. The vibration was present before I bought new tires and had the wheels balanced. One of my automotive instructors suggested having my drive axles balanced. Just looking for more opinions or any tests I can do. If I end up pulling the axles, are there any upgrades with which I can replace them?

Thanks guys

[jfd64]

Most of us have experienced vibration issues at various speeds.It can be difficult to pinpoint.New tires which can be slightly out of round from the factory and all new parts(which can be cheaply made) do not always solve this completely.They were not engineered to be driven 80 mph but more in the 55-60 range.One i had replaced all steering and suspension and tires but my alignment wasnt perfect so i would get a bad shudder at 55-60 that would smooth out at 65-70.Getting the alignment true straightened that out.(I always do my own alignments and for some reason that one gave me trouble).Doing a swap or going with spacers and bigger tires and wheels can really smooth things out at high freeway speeds.Just remember speed can kill faster ....especially in a festy.

[Sid_RallyX_82]

Found out the PO didn't have the last set of tires balanced -____- high speed vibration is gone!!! I almost miss it, though. I used it as my speed limit. Now I actually have to look at my dash to know how fast I'm going but she still shakes at around 55-65mph. I think it's cuz of my loose tie rods, but I guess I'll find out when I replace them