I am looking for suggestions on how to fix driveline vibrations. I have a 40 Chevy/GMC 302/T5/9inch combination that has major vibrations above 50 mph.
I have had the trans,driveshaft and rearend checked for runout. The engine,flywheel and clutch combo runs vib free when w/o the trans. The driveshaft angles are equal at both ends.
I have two front mounts on each side of the engine which are rubber mounted vertical posts off the crossmember. The rear mounts are standard chevy pads under each side of the bellhousing and mounted on a truck crossmember bolted across the chassis rails. The T5 trans is not mounted to the chassis. The engine/trans combo seems to be very solid in the car when gunned in neutral but it vibrates at high speed.
Any suggestions would be greatly appreciated Thanks, Frank H.