My car had a pretty bad vibration between 60-75 mph. I noticed that many of the wheel weights had fallen off so I took it to a local tire shop and had them balanced. The vibration improved but was still there.

I just took the car to the dealer for some other issues and told them about the vibration. They recommended doing a road force balancing on the tires. I was skeptical but they did it and the vibration is gone.

Apparently not all shops are equipped to do road force balancing. I hadn't heard of the term before. But from what I understand, what they essentially do is index the tires with the wheels. Tires are never perfectly round. Wheels are never perfectly round. By indexing, they mount the tire with the high point of the tire opposite of the high point of the wheel to make the combination as round as possible before proceeding with normal spin balancing.

It worked for me and from now on, I'll make sure that any time I have my wheels balanced, they can do a road force balancing.

Thanks for the info. I'll have to do the same - I have the same exact issue.

Most if not all MB dealers have Hunter equipment, use locate link to find an independent in your area http://www.hunter.com/pub/product/ba...159T/index.htm

For the benefit of other members MBUSA covers RFB for the first 12 months or 12000 miles (whichever comes first) for all new vehicles. Furthermore, always request RFB when replacing tires.

Hope it works as well for you as it did for me. I've messed with cars for years and never heard of it.

Thanks for the link- nice to read a little more about it and see what the machine looks like.

Oddly enough, the original tire shop I took my car to apparently has one of these. I guess they didn't do a road force balance by default?

Having taken their seminar twice, once in 1996 at St. Louis and later at their training facility in Sante Fe Springs California, I feel that there is no finer system to use for balancing providing the machine operator knows what
he is doing and follows the instructions that are shown on the balancing systems' computer screen.

In particular, the "road force" which is expressed in pounds. Once had a tech not pay attention to a reading of 35 pounds! Went and got the shop owner and he took over, and after he did what the computer told him to do, the "road force" reading was down to 13 pounds. That was the one Michelin out of the four new tires and after market wheels that had not been properly and correctly mounted and balanced by Tirerack.
Tirerack payed me for the rebalancing when I complained.

Go to the URL mentioned earlier by konigstiger and read everything you can about how it works and educate yourself so as to be able to tell if the operator does in fact know what he is doing and does it properly!

I have seen a nervous slight out-of-balance condition more than once on my son-in-laws E-420 (always with Michelins from Costco) and the Coats balancing machines Costco uses do not always get the balancing done perfectly. Sometimes, the fronts have been off by only 1/4 of an ounce on each side, and that was all that it took to correct the problem. Always at about 55 mph. Drives him nuts, but always the Hunter System finds
and corrects the issue.

Maybe that's the reason that so many high end shops pay well over $10K for the Hunter system.
It does get the problems solved.

HTHs

I;m disappointed. Had mine done with the Hunter, but I've still got vibration around the 60mph mark. Goes away around 70 mph. It was a non-MB tire shop, but I figured they would do a good job with the Hunter....

That is why it is so important that you completely understand what this system can do and be almost a
tech yourself so as to be able to tell if the person doing the work is simply doing all the
required steps that must be taken to be sure everything is balanced properly.

See:http://www.gsp9700.com/pub/images/demo.cfm

On the right, click on 'Operation Technique'

To study this video will take some time, but to me, it is well worth that time so that
you may be able to understand what is involved in properly using this system.

Dave is the fellow who conducted both of the seminars I attended.
This video was done sometime prior to my first exposure to the Hunter GSP9700 system back
in the summer of '96 when our group toured the Hunter Engineering facility in St Louis, MO.

Prior to then, I too had never heard of this superior equipment.

Believe me when I say,
"If the tech doing the balancing does understand the system and does do everything the computer
screen instructs him to do, it works, period! I have never seen the Hunter GSP9700 used when it
has been done correctly that the problem is not correctly diagnosed and the problem corrected."

Many times, when someone has complained that the Hunter System did not solve the problem,
I have discovered that the tech doing the work was not bothering to take the time
to do the proceedure correctly.

HTHs. Questions?

Bummer. But that's pretty much how my car behaved: bad vibrations between 60-70 and smoothed out after that.

Now after getting it properly balanced at the dealer with a Road Force balance, it's smooth at all speeds. An amazing difference. The car is much more pleasurable to drive now.

You could try complaining to the shop you took it to, saying that you still have the vibration. Or you could try the dealer and explain what you've been through and that you really need a proper and thorough RFB.

All the Hunter GSP9700s have that "Road Force" feature.
In fact, that reading in pounds will appear along with the recommended balance
weights required to be applied and their recommended locations.

What's happening I think it that the tech using the system is simply too lazy to follow
the steps outlined and do whatever it outlined. That's why it is so important for you to
understand what is required and to observe the operator while he is doing the work.

Doesn't surprise me that certain tech's would be lazy or even uneducated.

I wonder if some shops have more than one balancing machine - a GSP9700 and a lesser model and don't always use the GSP9700? I originally took my car to a local tire shop which claims to have a GSP9700 (based on Hunter's website) but at the time, I didn't know anything about them and didn't look inside the shop to actually see it. Maybe they never used this machine on my car at all?

As I have said repeatedly, the job is no better than the tech performing it.
Many low paid flunckies could not care less and will not do all the
steps that are required to fix any out-of-balance conditions.
Yes, some shops have more than one balancer and many shops do
charge a premium to do the job correctly using the GSP9700.

The trick is to find a shop that has a Hunter GSP9700 and charges
a fair price and does not overcharge as some shops do.
Ask the manager or owner if you are allowed to watch the tech doing the work.
If he says 'no' thank him and go elsewhere. If you are not allowed to
watch, how can you be sure the tech is doing everything as required?
That is the key. If the work is not done properly, you will most likely wind up with a slight vibration.
It seems that many MBZs and Bimmers are rather sensitive to the slightest out-of-balance conditions.
And with the larger diameter and wider wheels, the more that this can occur.

HTHs

Is this the same as the Discount Tire "Ride Matching" system?

And how much are you guys paying for the road force balancing? An independent shop with the GSP9700 wants $35 per wheel to do it. They're charging a premium because I have 19" wheels and 35 series tires. I called the local dealership but the receptionist didn't seem to know what road force balancing was and as usual, the service adviser was on the phone with someone else.

I believe most independent shops charge a bit more as the tire diameter increases. I recently had to replace a 19" tire on my Jaguar (with only 1000 miles on it!) due to a flat. The shop mounted and balanced it for $35 on the Hunter 9700 road force balancer.

Yeah and they said they have to take the tire off and possibly reposition it. So basically a full mount and balance.

I recently bought new tires from Tire Rack and rims from another supplier. I chose an installer who had a good reputation for mounting and balancing tires. Well to make a mistake go away, the installer was not able to correctly balance the tires. 245/40/19 and 275/35/19 - these are big tires! I should have given the installer the business who had the Hunter GSP9700 Roadforce balancer. I had to after the vibration from the 1st installer tires improperly balanced. The new shop took me in to the machine and showed me what they do, also told me every weight was placed wrong for the rims and tires. Yes they felt sorry for me and charged me only $30 per tire, he said they usually charge $40. The car is as smooth as silk above 100.