Chevrolet Repair: 1965 C20 3/4 ton truck - front vibration, steering wheel shimmy, steering dampner

Question
Hello -

I have a 1965 chevy truck.  If I go over a bump in the road at any significant speed (20mph +) I get severe front vibration.  The steering wheel shimmy's back and forth probably 20 degrees to each side, and the truck sort of "bounces".  I can only stop the vibration by bringing the truck to a complete stop.  It shakes like crazy.  If I drive slowly over bumps, I can prevent the vibration.  

This is a fairly infrequently driven vehicle.  I would almost suspect the steering dampner, but am trying to figure out a proceedure to verify what is truly wrong: could it also be a king-pin, tie-rod, joint issue?  

Answer
Hello Karl,
Pull that dampener off, and try it as a muscle builder. Pull and push it in and out. It should have no easy spot...not even for an inch. That is probably what is needed.
Having good shocks, tight tie rod connections,(Grease helps), a good idler arm if it takes one, and balanced tires all helps.
Adjusting any excess play out of the steering gear box can also help.
But pull the dampener loose, and see about that lack of tension in it. Probably in tha straight ahead area of its travel.

Van