: tire balancing, particularly at high speed



ualdriver
11-07-05, 06:00 PM
I recently purchased new tires for my V and had them mounted and balanced at the local Discount Tire shop which was the only place in town that could remove our stock EMT tires. Anyway, they mounted and balanced the new tires, but now I can't help but notice that around 75-80mph (normal highway cruising speed for me) there is an ever so slight vibration being transmitted through the steering column (it's not the road as it seems to go away below 50mph). You can even see the steering wheel going back and forth ever so slightly if you look down at the wheel. I don't remember if this vibration or the visual movement of the wheel was the same with the "factory" balance job, but I'm pretty sure it's worse or I probably would have noticed it before with the old tires.

So I guess my question is this: What's the best way to get ones tires/wheels balanced so that these higher speed vibrations can be elimated? This is the second time that I've received a less than adequate balance job at this shop. Are there places that are better equipped to balance ones wheels/tires so that at the high speeds we normally travel the tires/wheels won't vibrate as much?

Thanks,
ualdriver

1MEANV
11-07-05, 06:03 PM
get the tire shop to do the job right

1MEANV
11-07-05, 06:04 PM
maybe their tire machine is crap!

Lindsay Cadillac
11-07-05, 06:08 PM
You may have an issue with road force variation. What happens in some cases is that the tire changes once it's placed on the car in a loaded situation. There are machines out there that have the capability to check this. Chances are since they were new tires they didn't check this, they probably just spin balanced them.

First thing I would do is find out if the shop you used to mount and balance the tires has one of the machines that can do this. If they do find out if they performed a road force balance on your tires, if they didn't then that's the first place to check.

If they already did a road force balance then you'll need to start looking in other areas, possibly a bent wheel or a front hub/bearing problem...

skepticman
11-07-05, 07:56 PM
This site (http://www.gsp9700.com/) allows you to search for local shops that have a road force balancer.

When I had my painted wheels replaced with polished wheels at a local tire shop, they supposedly balanced them. But when I had my tires rotated and balanced a few months later at my dealer, they must have used this machine, because there was a dramatic reduction in vibration at high speed afterward.

ualdriver
11-07-05, 07:57 PM
OK, I should take it to the shop and ask for a road force balance. I'll give them one more shot and mention that to them. I'm pretty sure they only did a spin balance as that's what it says on the receipt...

skepticman, I checked out that site and lo and behold, that same tire place has that machine. I'm going to have them use it when I take it back in.

Just out of curiosity, if there is a defect in the wheel or tire that is causing the problem, how is that diagnosed? Basically trial and error eliminating other causes or can a tire/wheel shop examine the wheel and/or tire and determine a defect with either?

Thanks guys for the info.

Lindsay Cadillac
11-07-05, 09:41 PM
The Hunter machine will tell you if there is a problem with the rim, tire or both... So if they road force balance all the wheels/tires and you still have a problem then you know to look elsewhere... The key is getting the road force reading as low as possible. GM says less than 18 lbs for passenger car tires is the limit. We try to get the reading as close to 10 as possible, usually by rotating the tire on the rim.

Ryan's '05-V
11-07-05, 09:49 PM
I had the same issue and road force balancing helped my issue but now i have a vibration around 60. My wsteering wheel shakes pretty bad but this should be a separate issue.
If they have one of those machines, tell the place do road force balance them for free or split the cost as my place offered to split the cost as it should have been offered when the tires were installed. The didn't realize the V would be so sensitive.

Merle Corey
11-07-05, 10:33 PM
[quote=skepticman]This site (http://www.gsp9700.com/) allows you to search for local shops that have a road force balancer.

Dang and THANK YOU! Brilliant, simply Brilliant :sneaky:

Sea Bass
11-08-05, 01:16 AM
I had/have the same issue with a Toyota Tacoma of mine. Replaced the stock tires, and at 65-70mph the steering wheel vibrated, the automatic floor shifter jiggled and the car vibrated slightly. Also, the car veered to the right when I let the steering wheel free.

Discount Tire/America's Tire Co. provides free rotation and balancing.However, they do not do alignments.I took my truck in thinking it was an alignment, and all it did was slightly fix the veering to the right.

I'm 95% sure that Disctoun Tire/America's Tire Co. only does spin balancing when putting news tires on.

JKG
11-08-05, 07:59 AM
I had new tires placed and consistent problems with vibration in the steering wheel above 50 mph. The problem is mostly solved by rebalancing the tires over and over again - took a bunch of trips to 2 different tire stores. Just needed a spin balance. problem ended up being one wheel was 2.5 ounces off, which is apparently enough to make a vibration.

the interesting thing is that a shop would balance a wheel, and then redo a few days later and find it was off an ounce or so. Makes me wonder about the accuracy of these machines.

CTSVONFIRE
11-08-05, 08:39 AM
Road force is a big issue w/ tires
Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation.

The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide:

P-Metric tires of passenger cars
18 lbs or less

P-Metric tires on light trucks
24 lbs or less

LT-tires on light trucks
30 lbs or less

This is what GM says are standardsfor road force, and warranty purposes. I have replaced many tires on those new H3's. Some trucks would get a whole set straight from the factory.

CTSVONFIRE
11-08-05, 08:41 AM
Lindsay Cadillac knows what I'm talkin about 10lbs. is an excellent tire. If you've ever had vogue tyres you would be lucky to get one that was good.