Triumph Repair: Vibration at Speed, suspension bushings, speed vibration

Question
Jim, my '73 TR6 produces a vibration particularly worse from 50+ Mph.   

Not sure if this is related but at very low speeds when slowing to a stop, I notice that my front end (when viewing the left fender as a reference) has a subtle back and forth sway.

Thanks, Ed

Answer
Ed,

If you're getting a low speed sway it sounds like either a bad tire or one of the rims is bent.  The higher speed vibration could also be a tire out of balance.   Not necessarily the left front, that's just the corner that you can more easily watch.

A quick test would be to jack up the car (using proper supports for safety of course) and slowly spin each wheel and carefully watch the rim where the tire bead sits to see if there's obvious movement.  Also keep an eye on the tire to see if there is an obvious bulging or distortions.

Another potential cause for the problem is worn suspension bushings.  While you've got the tires up in the air it's not a bad idea to take a peek at the suspension bushings and the trunnion bushings.

Cheers,

Jim