My 40 Chevy/302 GMC/T5/Ford 9" has developed a high frequency vibration around 60 mph, 3000 rpm in 4th and 2000 rpm in 5th. The driveshaft has been balanced, the angles are equal and the rear end play has been checked by professionals but the vibration is still present. The rear motor mounts are under the bell housing and two front mounts are on each side of the engine and all are in good shape.
Has anyone had vibration problems coming from the T5 trans? May be a bearing? This is a high frequency vibration that shakes the shifter as well as the clutch and brake peddles.
Make sure that a weight hasn't slung off of the driveshaft. It has been known to happen. The guy may have only tack welded in to the shaft as he was finding the right amount of weight to get it close enough to get it in range, and just never went back and fully welded it on. It can also be a bent mainshaft in your tranny, especially if it came out of a Camaro or Mustang.
