Three Out Of Four Tires Out of Balance After 5k!

[The Critic]

On the day before Thanksgiving, my father and I took the Altima to America's Tire for a tire rotation. The Altima had 5,475 miles on it and still had the original Bridgestone Turanza EL400 tires mounted. I was only expecting to receive a free tire rotation, but the crew at America's Tire were gracious enough to also rebalance all four tires at no charge.

America's Tire used a Hunter QuickMatch balancer with the Smartweight feature. As it turned out, all tires except for the RR tire were out of balance by more than an ounce. Although I never noticed any vibration on the highway, the ride was slightly smoother after the rotation and balance.

So, does anyone have an idea as to why three out of the four tires were out of balance? The only reason I can think of is that the tires had "slipped" on the rim, which caused the tires to be out of balance. However, the tech did mention to me that on one of the tires, he only had to move the weights over by an inch, so it is possible that the weights were not installed correctly when the tire assembly was balanced at the factory.

Thoughts?

 

[D Hill]

It's not common on decent tires (and I would definitely place Bridgestones in that category) but it happens. I have about 8K on a set of Kumho Solus tires on my Accord and they need to be balanced. They were rotated once at 4K and then last week, when I started getting the vibration. I've had Kumhos on two different vehicles for over 100K and never had them go out of balance this fast. But it is possible that a weight was thrown off.

 

[Hallmark]

With less than 6,000 miles on the vehicle, it would appear that the car left the factory with three unbalanced tires. You have correctly diagnosed misalignment as unlikely, but slippage of the tires on the rims would be even less likely to occur on the Altima.

Blame can most probably be placed on the assembly line in your scenario.

 

[pottymouth]

It is not all that uncommon for tires on a brand new car to be balanced improperly.

 

[hounddog]

Bet you can use a different balancer in 5k and some will show somewhat out of balance again.Tires don't slip on a rim.Back in ancient days they could but not in 4 decades or more.

 

[CapriRacer]

Originally Posted By: The Critic
........America's Tire used a Hunter QuickMatch balancer with the Smartweight feature. As it turned out, all tires except for the RR tire were out of balance by more than an ounce........So, does anyone have an idea as to why three out of the four tires were out of balance? .......


Yes, it was at the very least this: "....Smartweight feature....."

This uses a wider tolerance for lateral (dymanic couple) imbalance and the result is a different answer than "perfect".

If you consider what happens in a dynamic balance procedure:

1) The amount of weight needed to statically balance is calculated - one weight- but you can think of this as 2 weight split 50/50, one on each side.

2) The amount of weight needed to dynamically balance is calculated - 2 weights, 180° apart on opposite sides. This results in 2 weights on each side.

3) A vector addition calculation so that only one weight per side is needed.

Usually cars are insenstive to static imbalance of less than 1/4 ounce. So if you get it with 1/2 ounce, you're good to go. But cars are even less sensitive to the dynamic couple imbalance and "Smartweight" takes advantage of that by allowing more freedom in the calculation. The net effect is less weight is added.

While it is also possible that the factory was only statically balancing, I don't think that is the case.

Bottomline: The tires and wheels were not "Out of Balance", they were balanced to a different tolerance level. I would guess that if you took any car fresh from the factory and used the "SmartWeight" feature, 75% of the tires would get a different answer.

In the days where I was a rep to Ford, Ford used static balance only on its pickups, vans, and SUV's. There was a common misconception that the factory didn't know how to balance tires - or that the factory equpiment was out of calibration - but the real answer was that the dealership was doing dynamic balancing, which results in a different answer.

 

[Craig in Canada]

A couple of things:

1/ the factory is not always the best at a lot of things. I've read lots of stories of brand new cars having alignments that were way off too. There's no reason this couldn't apply to tire balancing, but it is perfectly reasonable to expect them to do this properly.

2/ Different tire techs have spoken to me about tire "break in". They might be all trying to sell additional balance visits but different stores have told me not to be surprised if one rebalance was necessary after some break in mileage (like one season on a set of snows). I have witnessed something like this from time to time - they'll start balanced and then after a couple thousand kms the construction has "settled in" and one rebalance is required. After this the tire may be fine for its lifetime with no additional balancing. (My tire "lifetime" is probably shorter than many, though)

3/ It's not uncommon at all for a roadforce balancing machine to say that a non-roadforce balanced tire was out of balance. Road force machines do a better job of balancing - if they didn't specify that the weights be different, they couldn't be any "better", right?

4/ having the wheel slip within the tire is certainly a possibility for tire replacement but not too likely from the factory. Once, years ago, being dumb, I did it to myself. I'm now more careful about this sort of thing. Generally now when I need new tires I do it in the off season for that set and just take the wheel assemblies in to the shop instead of the whole car. The mounting compound has weeks to months to dry before I drive on them plus no one else has to touch or lift my car and I don't need to wait around while they work.

 

[Sayjac]

Quote:
I was only expecting to receive a free tire rotation, but the crew at America's Tire were gracious enough to also rebalance all four tires at no charge.
And that is indeed extremely gracious, IMO. I've had DT rotate my OE tires for free many times, but they've never 'offered' to do a free rebalance, nor would I expect it. But, it's hard to surprise me now about the quality of the service DT/AT provide, many times for free.

As for the balance, yesterday I had a set of wheels installed on my daughter's car from a DT grand opening promo special. Got talking to the manager about the machines they use (new store), and asked if they still had a roadforce machine. He said in the Charlotte NC area they no longer do 'roadforce' balance or have roadforce machines. I asked why, and his answer was because "they couldn't do anything different/better" than the machine (Quick Match) that they use. Didn't completely understand the answer but thought it was interesting to hear. He mentioned that some Bimmer owners had had there tires rebalanced at DT after a BMW roadforce, and were more satisfied/felt better results. Perhaps CapriRacer could weigh in on this point?

Also got talking about Nitrogen filled tires. He said a large number of folks in this new store area are convinced of it's merits, I laughed. The new car dealers in the area promote it like mad, here's how. They tell the mark that the ~$30 will save them "a tank of gas a year."

To which I responded, perhaps if they're too lazy to check there tires every 4-6 weeks. He said exactly. He said his new strategy at this store is going to be, that he'll save them a tank of gas a year for FREE, if they come by ~once a month and have their tires air pressure checked for free.

Further he said, he is doubtful that the dealers are flattening all tires and refilling with Nitrogen. Implied they may be just be putting some N in, using different valve cap on and sending it on it's way.

I said I'll be be sticking with the free 78% variety, and checking my air pressure.

Needless to say, generally enjoy and find something interesting to talk about on my trips to DT.

 

[CapriRacer]

Originally Posted By: sayjac
..........He said in the Charlotte NC area they no longer do 'roadforce' balance or have roadforce machines. I asked why, and his answer was because "they couldn't do anything different/better" than the machine (Quick Match) that they use.......


Let me stop right there. A "QuickMatch" machine IS a "RoadForce" machine with a couple of extras! It's Hunter's newest version. If he can't get that right, why trust anything else he has to say!

..........He mentioned that some Bimmer owners had had there tires rebalanced at DT after a BMW roadforce, and were more satisfied/felt better results. Perhaps CapriRacer could weigh in on this point?....[/qote]

I call "Poe" on that! That is, some folks will believe anything you tell them, no matter how rediculous it is.

 

[Kuato]

Originally Posted By: Hallmark
With less than 6,000 miles on the vehicle, it would appear that the car left the factory with three unbalanced tires. You have correctly diagnosed misalignment as unlikely, but slippage of the tires on the rims would be even less likely to occur on the Altima.

Blame can most probably be placed on the assembly line in your scenario.


+1. It wouldn't be the first time that there was substandard prep on a new car.