70LT1

At higher rpm settings (over 2500 rpms) I feel a vibration in the car. At highway speeds if I engage the clutch and the engine rpms drop the vibration goes away. Does this sound like worn motor mounts? or should I expect continuous vibration from the motor at higher rpms?

BB wowbagger

I would check the trannymount to begin with :cheers: :smash:

TJRed76

My car had the same problem. I found that I had a broken motor mount, a tire with a broken radial band, and a balance weight missing from the passenger side half shaft.

Through trial and error, I found them one at a time, but that darned vibration didn't go away until I discovered the broken motor mount.

The way I found out about the motor mount was when I was having the carg rebuilt. The guy that rebuilt the carb. got in and did a power break to show me the increase in power. The hood was up, and the left side of the motor came up about 3 inches.

New motor mount, new ride. ;)


[Modified by TJRed76, 7:50 PM 1/23/2003]

redwingvette

The safe way to check for a broken mount is to place a jack under the motor and slowly lift it until you see if one side pulls away from the frame. Do not lift it high enough to pick up the front of the car. :lol:

gkull

If your have a stock damper check and see if it's broken between the inner and outer ring. You might also just have a flywheel/clutch/pressure plate out of balance problem.

Your problem is rpm related so it eliminates quite a few things.

Magic Fingers

I had the same thing happen, ended up being a worn input shaft bushing in the rear of the crankshaft causing the clutch to rotate out of balance.