Factor

Hi all!,

Sooo did a full frame on restoration on my C3...(will be posting pics when the stars align and I can get a sunny midwest day AND be off work)...

did all new suspension and upgraded items as well...

sooo i noticed that at 55mph...NOT 60 or 50...that the front end starts shaking! like a wiggle...but it is noticeable as it vibrates the windshield!..I can see the a-pillars move...BUT at 60 it goes away?!?

I rotated the tires thinking it may be off somehow?...no change...what suspensions components could be the culprit?...I thought maybe the tie rods...BUT i measured them exact when changed...

I did change rotors to drilled/slotted...but stock calipers...new hawk pads...would a wheel bearing get goofy like this?

Would love the thoughts....(car should return from cleanup on wednesday)...

Thanks!
Ron

AirborneSilva

Did you get an alignment?

blue by you

wheels need to be balanced

dochorsepower

I think you are seeing the natural frequency of an old Corvette frame. Many people have performed a lot of welding and gusseting to stiffen the frame.

Jud Chapin

hugie82

Since its only at 55 a tire or driveshaft would be the culprit. After years of being a doubter and beating my head against the wall to find a shop without a retard operating the balancer, I found those tire beads really do work. You can find them for a good price on Amazon or eBay. I took my wheel off that was balanced but still had a little vib at @80mph and I used my truck to run over the edge of the tire to pop the bead. Put the beads in, reinstall the shrader valve, air it back up until the bead seats and reinstall. Smooth as glass.

BlackC3vette

Just to eliminate it as a problem, check the tranny mount tightness.

diehrd

You have a broken belt in one of the tires .

doorgunner

I have also had a new shock that was defective/weak.....cause the same problem............compounded by a tire that was not balanced correctly (as another member stated).

Factor

GREAT INFO!!!

Of course...I somehow missed those!!!

Gonna start on down that new list! THANKS!!!

TX-Techman

I agree with a tire or wheel issue. I had a similar issue on my 69 and really assumed it was just a normal characteristic of a 40+ year old car. To my surprise the issue miraculously went away after replacing the wheels and tires.

vettebuyer6369

I've been chasing a vibration at 52 MPH... Replaced a bunch of parts that I think needed replacing anyway, but it was fixed with new tires.

midigike

For giggles I would check over the whole front end just to make sure...
But knowing from my tire buster days, I think your one tire is the issue. I learned that you always don't have to put weight on the rim to correct the balance, tires are sometimes heavier in one spot and you can spin the tire on the rim, spin it on the balancer, get it closer and most times it will require LESS weights, and that will make a huge difference in balance. One of my pet peeves is when I see a wheel with 10" of weights on one side. All tires are different and the harmonics of that tire can happen at 40, 50, 55, 65 MPH or what have you. Was the car sitting for awhile, are the tires flat spotted?

Factor

Car has older tires...odd...before I did the frame on resto, no issue...but I am waiting on Boss338s... will have all new shoes!

I will double check the trans mount and get aligned after the new wheels!

Thanks!

doorgunner