Got a little vibration at 90-100 MPH...

[turbosam6]

What should I look at first? Wheels/tires out of balance? It rides smooth below that speed, so I would think the tires are OK.

How smooth should the ride be at high speeds anyway?

The car has 30K on it and is basically stock. I've been doing maintenance on it since I bought it (fluids, etc) and haven't seen any play in any of the suspension or anything. Motor and trans mounts look OK too.

[-FROG-]

Usually with mustangs, when we would get vibration at higher speeds, it was the drive shaft getting lose. To test it... Put the car in neutral when you are feeling the good vibrations. If it still does it, then the problem is past the tranny and more drive line associated. So then it can be your drive shaft, half shafts or tires. This will exclude the problem being your tranny or motor, although it may be a motor mount... but kinda doubt it.

[plumcrazy]

balance the tires

[bushido]

Also check the tire pressures..

[turbosam6]

It does it in neutral as well, so its driveline related. Haven't checked tire psi in awhile, good idea.

[Paolo Castellano]

Originally Posted by plumcrazy

balance the tires

Plum's got it right:!

[crazykane]

my car started doing that. I had a wheel that way out of balance. I run low pressure at the track think the tire spun on the wheel.

[1TONY1]

Originally Posted by plumcrazy

balance the tires

Road force balance !!! Oh yea...check that other crap too

GSP9700 Road Force Measurement System