Hi. I purchased a 66' coupe a while back and have working on it with my dad. It's a pretty good car but there are little things that we really want to fix; one of these things is that the steering wheel shakes like crazy at exactly 40 mph and then it will stop once it gets past 43 mph. It will be running smooth until it gets up around 40-43 and then the wheel goes nuts. If anyone has any idea what it could be, I'd appreciate the help.
Kevin

 

have your wheels re-balanced

 

maybe you have a broken belt? belt in the tire. or maybe just an unevenly worn tire? Wheel shake should mean that it's the front tires, specific speed should mean something wrong with the tires themselves. Try rotating them to the back. If that solves the problem, look over the tires very carefully, if they seem ok, have them balanced.

 

in addition to having the front wheels balanced, you might want to check the idler arm bushings for excess wear also. and really bad front shocks could be contributing to the problem also, but I think tire balance is the first thing to check/fix.

 

i had a vibration like that too they fixed the ti-rods the idler and rebalaced the tire... still wouldnt go away so he thought it was the rotors out of balace so put new ones on and it s gone