Bad vibrations!!

[Sweeet Ride]

I have a vibration in my Mustang (1967).....can't feel it in the steering wheel but you can feel it in the seat of your pants. At high speeds (90mph +) the car almost shakes apart....more like a violent shudder but...still can't feel it in the wheel. Thought it was my old Crager rims at first but I think I should feel that type of a vibration in the steering wheel.
Any ideas??

 

[jcode68]

Do a search in this forum and you should get quite a few hits. If you feel it in the seat, good change your drive shaft is out of phase - have you removed it replaced it recently? Could also be U-joints and a few other things I'm sure others will suggest you check.

 

[Sweeet Ride]

Do a search in this forum and you should get quite a few hits. If you feel it in the seat, good change your drive shaft is out of phase - have you removed it replaced it recently? Could also be U-joints and a few other things I'm sure others will suggest you check.

Notice you are running a stroker with AFR's.....I just completed the switch into my 67 fastback.....408 Eagle bottom end with AFR 205's. Its a screamer.....only have a few hundred miles on it yet so we are still doing some tuning but I think it will run high 11's if I could get it to hook.
Aren't strokers fun.....(and a handfull)....love the instant throttle response....scares the kids in their rockets!!

 

[zookeeper]

My rule of thumb is, if you can feel the shake in the wheel, it's the front of the car, if you feel it in the floor or seat, it's the rear. If you feel it at freeway speeds, but it goes away when you let off the gas, it's u-joints. None of these rules are fail-safe and I've had stuff like worn water pumps cause vibrations that were a pain to find.