There have been a lot of threads over the years about how sensitive our cars are to wheel balance, and how Hunter Road Force balancing is often the only way to get our cars to run smoothly on the highway. I don't intend for this thread to focus on that, but rather, this is about my challenges around getting a good road force balance. Maybe my trials will help others.


Bottom line, if you have vibration at speed and think it is wheels out of balance and you get a hunter road force balance done, and still have vibration afterwards, don't assume it isn't still a wheel balance problem.


On my 2004 XK8, I had the standard 18 inch factory rims. I replaced them with the Aris style rims that were standard on the 2005/6 XK8. I had the wheels trued by a reputable professional alloy wheel specialist. Then had new Goodyear Eagle F1 Asymmetric tires installed, with a hunter road force balance. I drove it part way home and returned to the shop to have them re-balance them. This time the balance was a little better, but not correct. I went back a few days later complaining, and I told them I wanted to be sure they were doing both radial force and lateral force, and that I wanted the balance to not just be "within spec", but to be as close to perfect as possible, even if it means they break the bead, rotate the tire on the rim, and check it again. They tell me this time they got it right. I drove home, it still was vibrating at speed. So I go back to the same shop and with calm assertiveness I told them that this was the last chance for them and I would want a refund on the road force charges if not resolved. I told them that either the tech is not paying careful attention, or the road force machine is out of calibration, or both, and that I wanted them to re-calibrate the machine before rebalancing my tires. They did re-calibrate (I watched from outside), and then re-balanced all four wheels. They did have to rotate one tire. They told me all were off balance when they checked them initially after the re-calibration. This time, the balance is perfect, there is no more vibration on the highway and it is as smooth as silk.


I will add that they actually told me prior to the last re-balance that they were not going to do it again, and that the problem had to be my rims or the car. I told them there was no vibration with the old rims, and I showed them my receipt for the alloy wheel repair/true up, and it was at that time that they agreed to calibrate the road force machine and do the wheels again.


The morale of the story is, don't assume the shop knows what they are doing. Don't assume the road force machine is working properly. And don't give up, demand perfection, it is worth it.

 

Good for you! At least they finally got it right. Did they apologize for wasting your time playing at it twice before getting serious the third time around?

 

Of course not.

 

Typical.

 

This is yet another reason why I value my long-time relationship with my trusted tire service provider. I know them, they know me, and they realize my wife's XK8 is hair-trigger sensitive, my S-Type much less so, and my Dodge Ram pickup is happy to just be in the neighborhood....

When my wife bakes her holiday goodies at Christmastime every year, I take these guys a nice gift tin full of them. They appreciate that and it always shows with the way they treat me and respect my opinions and requests regarding the wheels and tires on our vehicles....

 

Jon,
I'm guessing you deal with Discount Tire?

 

Rotating the tire on the rim is pretty standard to get a perfect balance. I have also found that some tires are much easier to balance than others.

Like you, I believe the Hunter equipment driver makes all the difference.

 

Mike,

Yes indeed, one particular Discount Tire store about 10 miles away from me. They're the best tire and wheel guys I've ever dealt with. I won't go anywhere else....

 

I can't say enough about Discount Tire and their customer oriented approach to business. I've bought tires from them in the past and couldn't believe the level of service provided by them here in Asheville. My neighbor who knows nothing about cars ( he was a great attorney before retirement) called me one day about a problem tire on his Mini Cooper which has run flats because like other car companies they don't supply spare tires. He was going to have it carried on a flatbed truck down to Greenville, SC (70 miles) to have the Mini dealer handle the repair (no Mini dealer in A'ville). Guess what---both BMW and Mini don't repair these run flat tires---they replace them. I told my neighbor that I would pop up to his house with my hydraulic jack and pull the wheel off and take it to Discount tire to see what they could do. Discount also advises that the tire can't be repaired but said they would order the special Dunlop tire and put a temporary tire on his rim until the Dunlop was delivered to the store. My neighbor pulled out his credit card and the service adviser told him we don't need that yet wait till your tire comes in and we'll just charge you for the new Dunlop--this temp. replacement is just to hold you until we finish the job----my neighbor just became the biggest commercial for Discount Tire in the neighborhood. Goes to show you what a little extra customer service buys a company in the long run---me thinks some Jaguar dealerships could take a lesson along with a million other businesses!

 

There are a number of factors at play here. The road force balancer is a great tool but expecting to find anyone well trained and experienced to correctly operate one at a tire store is like trying to catch a saltwater fish in Oklahoma. Most tire stores have a revolving door for new employees and teaching them road force balancing amounts to a a ten minute "Uh, then you do this..." from another tire buster or the assistant manager. They don't understand what is really going on.

Charging $100 to road force balance four tires is a huge mistake - many times it takes much longer to do the job correctly and is't profitable for the shop owner. Off car spin balancing is rarely done right for $10/tire, no reason to expect road force balancing to be done right at $25/tire. You may think the machine tells you what to do but you'd be wrong. It 'kinda tells you what to do'.

Hunter 'kinda states' 25-30 pounds of 'road force' to be a reasonable spec but I'm here to tell you there are quite a few cars where that won't fly. At a Lincoln dealer I used to work at we couldn't/wouldn't let a Navigator go with more than 15 'pounds'. (road force 'weight' is not really a weight like a 10 pound bowling ball swinging around on a rope)

Think about this - you just bought some new tires that have been shipped around the world, stored in every conceivable fashion and geometric position, mounted by an almost professional 19 year old kid that probably just learned how to use that rim clamp machine a couple days ago and hopes nobody saw him kink the bead and tear the rubber just a little bit, oh, and also see that he didn't remove the old weights first and drug one of them around the rim, then forgot to install a new valve stem and accidentally drops one inside the tire, which he decides to leave, before successfully coaxing one into the hole with the tire still on the rim. Do you see where I'm going with this?

Now we get to the practical side of things. That tire had plenty of lube on it when it was mounted (at least you hope it did!) First time you jet down the street or hammer on the binders those tires are going to slip around the rim a bit - so much for your tire balance! But that's o.k., tires don't fully seat on the rim when first installed anyway. Going straight from the mounting machine to the balancer is a waste of time and money. You know how your car shakes in the morning until the tires warm up? What makes you think tires piled in stacks or sitting between two bars of a tire rack are ready to be balanced? They didn't ship these things half-way around the world gently squeezed between two cases of Charmin.

So, do you want to know what it takes to do a road force balance properly? In one visit?
This won't be a training how-to but a collection of steps required to be successful on the first visit.
1) Dismount old tires, inspect rims for obvious damage.
2) Mount each rim on road force balancer and measure run-out. Record on each rim.
3) Mount all tires and install on car.
4) Drive car in stop and go traffic and at highway speed for minimum of thirty minutes each to seat tires and warm the tread and casings (eliminating shipping 'dents' and cold spots, etc.)
5) Return to shop and immediately hoist car in order to not induce flat spots on cold concrete.
6) Remove tires, one at a time (don't want warm tires laying on their sides or treads waiting to be mounted on balancer) installing on balancer and checking balance and deflection then, after marking notes on tire, hang back on car temporarily. Proceed through remaining tires.

(Some newer versions/upgraded -read:more expensive - model balancers record some of this stuff but basically it all has to be done)

Now it's time to decipher the readings and parse the numbers. e.g. this tire has a 10, the wheel it's on has a 37. The numbers are about 40 degrees apart... the next wheel is a xx, its tire is a xx and they are spaced about xx degrees apart... and so on. Then, if necessary, you begin mounting and dismounting tires to alternate, better matched tire wheel combinations, re-checking, re-positioning and re-balancing. Yeah, Discount Tire is going to do this every single time it sells a road force balance package and every 19 year old kid is going to know how to parse this out and YUP!, you're only going to be too happy to watch junior peel out into traffic in your pride and joy while visions of the two parking lot attendants from 'Ferris Bueller's Day Off' dance through your head.

Have I struck a nerve yet?

Do you want to know how much they should be charging? First, eight years ago a basic force balancer was $10,000 ++. "++" means plus shipping, installation, training, accessories, advertising materials, etc. I think I made my point regarding tire store employees being able to successfully use the tool. Even if you should happen to stumble across one that was a dedicated to his craft individual do you think the manager would be happy to allow him the time to do it right? Maybe they'd let you take their rainbow colored unicorn down the street to the strip club that pays you to come inside and drink beer for free while all this happens. The only way this is going to happen, anywhere, for $100 is by sheer luck. Sometimes you get a good set of wheels, a good set of tires, maybe both. A good reliable mechanic at a good, reliable shop is/should be earning at least $70k/year (but rarely ever does) That good, reliable shop is probably charging close to $100/hr. (Smarter shops have caught onto the dealer's game of 'matrix' labor pricing - "How much is your labor rate?" "We only charge $75/hour." But they don't tell you that each subsequent hour is more and more expensive.) Figure some go easy, most don't. I expect an average time spent doing four wheels to be around 2-3 hours. I know how to do this the right way, have done it many times, and never look forward to doing to my own car. I do look forward to how it turns out, EXCEPT when...

You need to remember this only works on the tires and wheels. You know those $29 rotors you bought as a 'wholesaler close-out' from Amarockzonebay.youbet? Oh, and you forgot about that nasty pothole you hit that cost you $500 at the dentist? Or the 60 mph brake lock-up and skid junior did the other night? (I actually witnessed that one night. Junior just happened to 'slide' into a bar I was at one night. The next day his dad brought the car into a store I was managing back in the '80s. It was hilarious when I showed 'Pop' the flat spots on his new Gatorbacks when he came in complaining about vibration. His son - a friend of mine - came waltzing in to pick him up thinking the car would be in the shop for a while. I knew what was going to happen and took a few steps back and grabbed a water hose to break them up, just in case it got ugly) Then there's the whole driveshaft/u-joint/trunk monkey/delirium tremors thing, etc.

 

At least you're not cynical about it!

 

Beav is correct that no tire store is going to spend three hours Road Force balancing your tires down to the gnat's *** specs. But the three tire guys I deal with have been at their location for years, the Road Force balancing they do on my wife's XK8 definitely makes a difference in the car's smoothness and tracking, and here's the big reveal - they charge me nothing extra for the service. My tire purchase price from them is the same whether I choose Road Force balancing or not. And while I prefer to rotate my own tires at every oil & filter change I do, occasionally I take the car to them right after I've done an oil & filter change and let them rotate the tires while doing a fresh Road Force balance at the same time. All at no charge. Hard to argue with that level of service when it is costing me nothing extra....

 

Hi Steve,

I've just re-read your post and it is, without a doubt, an incredible informative (and humorous) essay on the subject. What it does point out, aside from the technical information it contains, is the marginalization of certain career choices in our culture.

There is a decreasing level of motivation for young men to go into the so-called "blue collar" professions which still, to a large degree, includes the auto repair trades. We in this country still cling to a "grease monkey" viewpoint regarding their children embracing that type of career. While we continue to turn out engineers who can design and program our four-wheel rolling computers, and a small number of technicians that are capable of diagnosing and repairing them, the number of entering the industry to mount and balance tires, and performing myriad other tasks necessary to keep our cars on the road, continues to diminish.

Your 19 year-old running the balancing machine is going to quickly figure out that there's not much of a future (or livable wage) attached to what he is doing, and will go out the "revolving door" you reference to seek a career elsewhere (but not, unfortunately, before he mucks up mounting and balancing your tires). Carpenters and electricians, as well as other construction-related trades, maintain an employment structure with a defined path upwards culminating in a well-paying career for anyone with the motivation and ability to take advantage of it. Sooner or later, the automotive repair industry will have to adopt something similar, or we'll all be driving cars that no one (except the dealer technicians) can repair, at an even greater cost than we pay now.

Sorry for the rant; just my two cents on the subject........

Max