Vibration/ shimmy help

[Ron H.]

I have a 65' 327/365 ragtop that runs great except I get a mid car vibration between 55-65mph. Under 55 it runs smooth, and over 65 it smooths out. the vibration is not coming through the steering wheel, and my car had an alignment a few months ago.

Any ideas

[Edward J.]

Re: Vibration/ shimmy help

Ron, , Have you checked the tires for proper balance? but it almost sounds like a driveshaft balance problem. Take the car for a ride and note the rpm range the vibration begins, Then with the car stopped In netural, slowly bring the rpms up to that range and see if the vibration is there. this will tell you if the engine is the problem or driveline has a problem.

[Timothy B.]

Re: Vibration/ shimmy help

Ron,

Try driving the car to get it to vibrate 55mph and move the steering wheel slightly left/right to see if the vibration goes away, front wheel bearings could be the culprit.

[William V.]

Re: Vibration/ shimmy help

If you do not get shake in the steering wheel, the first place to look is rear tire balance. If the tires are in balance then you need to dig deeper.

[Stuart F.]

Re: Vibration/ shimmy help

Probably not a viable problem these days, but it could indicate a tire with a broken steel belt. My second set of tires on my 63 were Goodyears that always had a vibration at 55 to 65 mph. Finally changed to a third set and the problem disappeared. We'd tried everything else before that.

Again not a common problem anymore.

Stu Fox