Demonator666

just like 455Man, I also have a high speed vibration. It starts at 58MPH, shaking the intire car. The flapper door on the 8-track rattles like crazy. The car has new rotors and drums, new tires (ballanced twice), new u-joints and ballanced driveshaft. The only thing different from factory specs is I went from 14" SSIII to 15" SSIII. Any thoughts?

Lady72nRob71

Would these wheels have snap on or bolt on caps? The wheels with snap ons need to be balanced with the lug nut holes securing the rim. The hub hole shape / location does not hold the wheel properly. The bolt on cap wheels could use the hub hole.

I assume good shocks and suspension components.

Demonator666

My old wheels had the bolt-on caps. The wheels on the car now have the snap-on caps. Rob, I don't understand what you're saying about the lug nut holes and hub hole location. Are you saying to have them ballanced on the car??? Oh, and all suspension parts are new. Thanks for the reply.

Bruce

Lady72nRob71

I have heard that these later wheels have to be held on the balancer machine with the lug nut holes. The nose of these wheels have a hole but it is not the right shape / size/ position for the balancer to hold them right. If the wheel is offcenter on the machine, the balance will be off.
I have seen these wheels put on a balancer and the fit is quite ill when held by the nose.
These wheels are known as "lug-centric", where as most wheels are "hub-centric". You might want to call around to see who can balance lug-centric wheels. Good shops know the difference. If they never heard of it, then try another place.

Demonator666

That makes sence...good information. I have not heard of this type of balancing. There's a shop in Fort Worth that specializes in old car suspensions. I'll give them a call. Thanks.

442_1972

I worked in a tire shop 20+ years ago and our Coats balancer at that time had various sized cones that worked with hub-centric wheels and a special adapter that allowed you to secure the wheel to the balancer when working with lug-centric wheels. I don't remember using the lug adapter that much, but I do remember that it was a pain compared to using the cones. One thing that I learned was to pay close attention to the lateral and radial runout of the tire/wheel as it spun on the balancer. Sometimes runout that was not directly the result of a bent or bad rim could be improved or corrected by breaking the tire down, spinning it on the rim, and re-seating it. I would sometimes do this same procedure, if the balancer called for a lot of weight to get a neutral balance. In some cases, I'd try another tire on the same rim to see if that would make a difference. I guess what I'm trying to convey here is that just because some weight can be pounded on a wheel to get the balancer to read neutral, doesn't mean the tire is properly mounted and balanced. Hopefully, the problem is simple to resolve!

AZ442

trany output shaft bushing on my 4 speed was my problum.

Rickman48

How'd you come up with that??

AZ442

after months of balancing wheels, replacing tires, replacing driveshaft and wheel bearings, the bushing in the ST10 4 speed was the cause of my highspeed vibration.

thanks for asking.

72hurst

Tire discount can balance the for you. Just tell them to use the "fingers". That's what they call them. I had mine balanced with them and I don't haveany vibrations at all.

elliseB

That was pretty interesting. It might be good for safety purposes.

Allan R

If the car ran smooth when the 14 SSIII's were on, it has to be the new wheels. Rubber shouldn't be the issue - it can be balanced. Are the wheels true? They can look good, but I'd check all of them or run out to be sure. I'd bet one of them is bent somewhere - inner or outer rim