WHY IS IT SO HARD TO BALANCE WHEELS??

[daniel812]

So its now the third time this month I am balancing my wheels on my 98 SLS. I still get vibrations around 55-65. Wheels are not bent at all and weights are all under 1oz. Tried rotating them and cross rotating them also. Should I try the stick on weights instead? Or is another balancer better, like if I go to a dealer? So far i have just been driving faster which works also.

[JimD]

If you have a wheel/tire balance problem, you could try to locate a Hunter GSP9700 balancer and an experienced tech to operate the thing. Hunter has a locator tab on this page.

http://www.gsp9700.com/pub/technical/4127T/4127t.cfm

Not all tires are created equal and out-of-round can be a problem. Also improper lug nut torque and torque sequence can result in strange behaviour.

[bigjayzway]

Do you still have the factory rims?

A lot of places are selling rims that are only 114.3mm bolt pattern, and telling Cadillac owners they will fit.

[Ranger]

Not all tires are created equal and out-of-round can be a problem.

I had one heck of a time trying to get my '02 SLS to run smooth. Even a RFB didn't do it. The solution was to get rid of the "square" Goodyear Integras that came with the car and put on a set of Goodyear Assurance Comfort Treads and have them RFB'd.

[OynxSTS]

As Ranger notes its not the wheels its your tires...

I don't know why people get all excited about a "balance" that takes little or no weight. A tire that takes 1 oz will vibrate just as bad a tire that takes 10 oz.

The key is low road force balance numbers. In the single digits. I would much rather have a tire that took 4 or 5 oz of lead and had a road force balance number of 2 then one that took 1 oz and had a RFP number of 20.

[wontgoslo]

If your rotors are slightly warped they also cause an imbalance. Now mine feels like im driving on a pillow top road ! ( slightly exaggerated)

[JohnnyG]

It's because your tires are not out of balance. For lack of a better description, it's more like they're out of round. Technically they can be somewhat out of round, but most likely they just have areas of the tread and sidewalls that "give" differently that others. In other words, some parts of the tire are stiff and some are soft. The rims can (and always will be) slightly out of round radially. Now this might sound like a bad thing, but it's not really because that's where the Hunter RFB machine works its magic. The machine finds the low spots on the rim, and matches them up with the stiff parts of the tire! Get every tire under 15# (less if possible) and you will have a pretty acceptable ride. Of course, if you get them down lower, the ride will eventually become glass smooth.

[JasonA]

This is why even the best spin balancing machines often fall short. They can't detect these variances in tire stiffness, or roundness. They can only balance the rotating mass. You could put a hexagonal tire on there and the spin balance machine would get it "balanced".

[OynxSTS]

It's because your tires are not out of balance. For lack of a better description, it's more like they're out of round. Technically they can be somewhat out of round, but most likely they just have areas of the tread and sidewalls that "give" differently that others. In other words, some parts of the tire are stiff and some are soft. The rims can (and always will be) slightly out of round radially. Now this might sound like a bad thing, but it's not really because that's where the Hunter RFB machine works its magic. The machine finds the low spots on the rim, and matches them up with the stiff parts of the tire! Get every tire under 15# (less if possible) and you will have a pretty acceptable ride. Of course, if you get them down lower, the ride will eventually become glass smooth.

BINGO. Nicely and accurately explained. The only thing I would add is that IMO 15# on these cars is TOO high and can be felt. You need to get the numbers less then 10#. I would refuse any new tire that is not in the single digits.

If you get this service done make sure you get the road force report that goes with it. This report will tell you what the before and after #'s are for each wheel/tire combo... It will also tell you the out of round for each wheel.

Have them put the best two upfront.

All useful stuff to know.

[daniel812]

time for an update..... I started by machining all four rotors since I felt a slight pulsation when braking. All four rotors were out of round. After that I recalibrated our wheel balancer and balanced all four tires again. The vibration is now gone although I cant say which of the two fixed the issue. I have Goodyear Integrity tires on the car and yes it has factory wheels. Thanks for all the advice and help, I really appreciate it

[Ranger]

I have Goodyear Integrity tires on the car

Oops, I guess I meant Integrity. Integra is an Acura. Duh.

[bc6t]

In addition to all of the great comments/information above, Badyear tires are not noted to be very true, especially for use on Cadillacs. This is why so many Cadillac owners have switched to other brands, especially Michelins. When I switched from Badyear LS-Z to Michelin Pilot XGT-HR - wow what a difference in smoothness and no vibrations at all.

Just something to consider next time you go tire shopping.

[daniel812]

Tom,

Thanks for the info. So if "goodyear" really isnt so good, how are they able to maintain their image and sell so many tires?

[OynxSTS]

Goodyear does make some nice tires and have over the years made some really good stuff.

The Gatorbacks, the EAGLE GTs, NCTs, Assurance, etc etc all very nice tires... many way ahead of there time in terms of technology...

Unfortunately, the RSAs that came stock on most of our cars...

Total crap! And not so cheap crap I might add.

[JasonA]

Both the Goodyear Eagle LS and Eagle RS-A are OEM-level tires (cheap tires that auto manufacturers buy for initial installation). It's unfair to characterize all Goodyear tires as bad on the basis of the often hated few tires. The Goodyear Integrity is another example of a very poor tire that is often installed at the OE level. As stated, Goodyear actually has some VERY good and successful tires out now, like the Assurance TripleTred and Assurance ComforTred. They also have a good Fortera light truck line. Their Assurance ComforTred is actually being used now as the original fitment on many Dodge Chargers (so they may be making "cheap" OE versions of that tire).

Goodyear certainly isn't the only tire company who sells cheap OE tires. Michelin's Symmetry is an often hated tire that is often installed at the OE level. The Michelin Energy LX4 is another tire that is popular as an OE tire, though it does seem to perform well in the aftermarket as well).

If you don't like the tires that came on the vehicle, don't blame the tire maker -- blame the auto maker. OE tires are designed as much by the vehicle manufacturer as they are the tire company. Cadillac would say they want the cheapest tire (emphasis on CHEAPEST) that will provide the best fuel economy and give a good ride. Performance/handling often isn't a concern, and treadlife is usually never a concern. Those tires just need to get you out the door. If they only last 20,000 miles, the auto maker doesn't care -- tires aren't covered by the vehicle's warranty (there is usually minimal coverage from the tire maker).

I think auto makers ARE realizing, however, that there may be some value-added to providing good tires right out the door. As stated, Dodge Chargers often ride on Goodyear Assurance ComforTred tires, and many new GM SUVs come with Goodyear Fortera light truck tires. These are often top-notch tires. The Goodyear Eagle RS-A is very overpriced and totally obsolete in today's market. I am surprised that Goodyear continues to sell it. Its new Eagle ResponsEdge tire probably blows that Eagle RS-A out of the water in every performance metric -- and probably costs about 75% of the RS-A's price too.