Originally Posted by SD Blue

That is the symptom, however, it would be a good idea to try an adjustment first. To adjust it, loosen the locknut and screw it in till you feel it just contact the rack. Then tighten the locknut. If you screw it in too far, it may become hard to start.

However, if you still have the symptoms, it may need replacement. After a while, the shake will get bad enough you will replace the dampener bolt. (I guess that is why they charge so much for it.)