I have a '67 vert 2v 289 with a C4. Engine was just rebuilt 5k miles ago, and runs great at slow speeds.
However, once I get above 50 mph or so, the car begins to shake violently, but not always. Sometimes it's as smooth as an Audi. When it does shake, I can really feel it when I put pressure on the shifter slightly to N or 2nd. The tranny does shift rather hard sometimes.
At first I just tacked it up to the age of the vehicle. However, I recently sat shotgun in my co-workes '65 FB and his was super-smooth.
Could this be the motor mounts? Loose connections where the tranny connects to the engine or driveshaft?
Please advise.
However, once I get above 50 mph or so, the car begins to shake violently, but not always. Sometimes it's as smooth as an Audi. When it does shake, I can really feel it when I put pressure on the shifter slightly to N or 2nd. The tranny does shift rather hard sometimes.
At first I just tacked it up to the age of the vehicle. However, I recently sat shotgun in my co-workes '65 FB and his was super-smooth.
Could this be the motor mounts? Loose connections where the tranny connects to the engine or driveshaft?
Please advise.