High speed balance issue?

[M_Six]

This past Saturday I took my brother out for a spin in the Zed. There's a very smooth and very deserted road here where you can see for two miles in any direction. It runs through miles of corn fields, which are empty this time of year, of course.

Anyway, we got up to 115 before I let off and coasted back down to 80 or so. There was a nasty high frequency vibration which I felt in the steering and through the shift knob from 115 down to 90 or so. I don't get it at all at more sedate speeds. Not till I hit 100 or so and it seems much worse coasting down from speed than it does under power. Could this just be a tire balance issue? Or might it be something worse, like with the tranny or drive shaft?

[MMMazing07]

could be:
-wheels need to be re balanced
-alignment
-if under braking its worse then = warped rotors

could be something else. get it checked at the dealer obviously. hope this helps

[O-cha]

He said through the shift knob? Did you mean wheel?

[reRESERVEDFX]

PLEASE DON'T!!!!!! Don't drive that fast thinking no one is there. There's a road here in Downers Grove, IL that runs for long and no one around... Until there was. I thank God he clocked me at 66MPH. I also got arrested but for non-arrestable offense. I'm pretty sure I will win the case but so much hassle for nothing. Go on a race track or a deserted airport field or something.

I just don't want you to see forking out the kind of money I have to now....

This seems for me like an alignment issue or just a road surface problem. Have it checked. A&L in Palatine, IL will do it for very good money and do it well. Make sure to talk to Anthony.

[BlackSapphireZ]

most likely the balance or if your suspension parts are worn(most likely not) that may be an issue

I love my car unfortunately 135 is as fast as I can go

[M_Six]

Originally Posted by O-cha

He said through the shift knob? Did you mean wheel?

Both, actually. In fact my brother in the passeneger seat said he could feel it, too. It's very noticeable.