Back in May I replaced my worn Hurst shifter, including all linkages, and had my transmission (M-21) rebuilt on my 69 SBC. The rebuild included replacement of the reduction gear, all seals, yoke, u-joint, etc.

Since the Hurst shifter is bolted directly to the transmission, I have always been aware of vibrations while driving. About a month ago, I noticed that after shifting into 3rd gear, there was a "new" vibration which remained until I hit 4th gear. The vibration would gradually go away after driving for a while.

I made an appointment with my mechanic to have him ride with me to feel the vibration. As you would expect, the problem persisted right to the front door of the shop. We drove for half an hour and it would not do it with him in the car.

Since then, I have isolated the problem. It happens every time I drive with the engine cold. After heating up, the vibrations stop.

I will be bringing her in for inspection tomorrow, then plan to put her up for the winter. I plan to bring this up with my mechanic at that time. Just wondering if anyone else has any suggestions as to what the problem might be.


Mark