Aftermarket Rallye Rims....

[AUSSIEVETTEMAN]

Guess who has just noticed that the aftermarket rallye rims we purchased 6 months ago, are not a snug fit?
:duh

While having a 'Bubba' moment :gap and trying to fit new lug nuts and stripping threads on two nuts and shearing two studs, trying to get the lug nuts off, I noticed that the new rims we purchased 6 months ago are not a snug fit. By that I mean that there is a 5mm gap between the hub and the wheel. My guess is that this is the source of my high speed vibration from the wheels. The rims are new and are not buckled in anyway, they have been balanced, all the drive shafts have been balanced and the diff carrier bushings and mounts replaced, but we still have vibration. My guess is that the lugs nuts are not centring the rim enough and when I measured it, it was out around the width of a piece of paper when comparing both sides opposite to one another. That would be enough to cause some vibration.

 

[lone73]

Lug-centric

I don't believe the wheels are supposed to be centered on the hubs. They center by the lugnuts.

I'd bet your wheels were probably hub centric balanced when the tires were put on. In other words the wheel was centered on the balancer with a cone shaped gadget that protrudes/spins-on into the center hub hole in the wheel. I have had bad luck getting a good balance with old style wheels using the hub-centric balancing method. If the hole is not dead centered on the wheel then they will be IM-balancing your wheels rather than balancing.

I always request that the shop installing my new tires lug-centric balance them. This centers the wheel on the balancer the way it is centered on your car- using the lugs. To lug-centric balance, they must install a part on the balancer that matches the lug pattern on your car, spin on a few lug nuts and then spin balance the tire/wheel.

They don't usually do it because it takes a little more time to find the right attachment for their machine and put it on. It probably doesn't usually make a difference on grandma's minivan but on a vette with those old style wheels I have noticed a big difference between a regular balance and lug-centric balance.

Not all shops will agree with me and probably many won't even do it for you (due to having lost their attachments long ago or just their being bazy lastards) but that would be the next thing I'd get checked to eliminate the vibration if it were mine.

good luck with it
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[Vettehead Mikey]

I don't believe the wheels are supposed to be centered on the hubs. They center by the lugnuts.

Correct.

 

[pgtr]

Have you found any particular shops (local, chains etc...) that consistently will or will not lug centric balance?

I think it's particularly important on some steel rims in particular. Yes I think it's just as important on some ol' minivan as a corvette

Excellent point - I was at Firestone just recently and asked about this and they only had 1 adapter.

 

[AUSSIEVETTEMAN]

Once again Mikey supplies information which is true and Lone, your in depth info was great!

I took the old girl down to the tyre joint once more to have the tyres balanced. The new locators we had made for the rims did not work. The lug nuts were not centring the wheels on the studs causing more vibration than we had before.

Monday morning she goes in to have the locators removed to help the lug nuts centre the rim correctly and WILL be lug centric balanced!

Thanks for the heads up.


Tony