This article on how to properly balance tire andwheel assemblies is the final 2012 installment in ourseries covering basic tasks performed in tire dealer-ships. The first in the series was an article on Basic TireRepair (February), the second on Tire Mounting/De-mounting (May) and the third on Tire Rotation (Au-gust). This latest article covers generally accepted prac-tices for balancing tire and wheel assemblies. It is in-tended not only for new tire technicians, but alsoveterans who want to brush up on their techniques. Photos, diagrams and background information

were supplied by Hennessey Industries’ Coatsbrand. The recommendations made in this articleare based on the use of a Coats 1250 tire/wheel bal-ancer. There are other brands of wheel balancers onthe market, and this does not mean that we endorseany one brand over another. We suggest that yousave this article – and the entire Back2Basics series– for future reference. It is important to note this article only applies toconsumer tires and does not address commercialtire applications – light or medium truck tires – orthe use of outside balancing aids that would be in-stalled into the tire/wheel cavity.

24 November 2012 | TireReview

FEATURE

TOM DUKEContributing Editor44Back2Basics

Step-by-StepTIRE/WHEELBALANCING

Background On Tire/Wheel Balancing

Tire/wheel assembly balancing isa very basic service, and still a goodprofit center for tire dealers who in-vest in the necessary equipment.

Modern cars and light trucks/ -SUVs are highly tuned vehicles, andanticipated performance, drivercomfort, fuel economy and tire lifeall can be negatively impacted byeven the slightest imbalance. Frac-tions of an ounce truly do mattertoday.

Current tire/wheel balancers aremuch easier to use than earlier ma-chines or the old-school bubble bal-ancers, with many automatic andcomputer-generated features de-signed to deliver exceptional bal-ance. Many modern tire/wheelbal ancers include features such asdirect drive motors, multiple balanc-ing modes, laser guides, automaticstarting with a cycle of se conds,weight storage bins and automaticstatic balancing.

There are a number of reasonswhy you should be checking the bal-ance of the tires/wheels on yourcustomers’ vehicles. The three basictimes when balancing should bedone include:

• When a tire is replaced or repaired

• When a balance weight is moved or falls off• When new tires are purchased

Tire technicians know that bal-ancing tire/wheel assemblies caneliminate vibration and wobbling.This will improve tire wear, inc -rease fuel mileage and removestress from a vehicle. Vibrationcaused by out-of-balance tires usu-ally occurs at speeds of 50 mph to70 mph. Consumers who onlydrive around town and not on ex-pressways may never notice theirtires are unbalanced, but damage isstill being done.

Today’s high-quality tires willhold their balance well unless anoutside force, such as hitting a curbor the loss of a weight, occurs.Technicians also should check tosee if a customer has locking wheellugs in some positions. Some lock-ing lugs are up to 1.5 ounces heav-ier than conventional lug nuts,

which may cause a half-ounce or sotranslation to the wheel.

Types Of BalancingIn many cases, when a tire is

manufactured, it is inspected forstatic and dynamic balance. Notevery tire, even among the majormakers, is directly tested, though.Tires that don’t measure up in ei-ther factor are rejected.

Tire manufacturers measurestatic balance by the use of a sensormounted to the spindle assembly,and measure dynamic balance bymounting a tire on a test wheel, ac-celerating the assembly to 300 rpmor higher and then measuring theforces of imbalance as the tire ro-tates.

In most cases, the old-schoolbubble balancer is a thing of thepast. Dynamic balancers – also re-ferred to as “spin balancers” or“computer balancers” – are themost prevalent piece of equipment.Even among dynamic balancers,though, there are vast differencesin not only features but, more im-portantly, precision.

Dynamic balancers not only de-termine the location of any imbal-ance, but also point out the exactamount of counter weight thatmust be added to correct the imbal-ance. Various available equipmentfeatures can make that an evenmore precise operation.

Road force variation balancing isyet another method that has beenin use at the OE level for manyyears. While only in limited use inthe aftermarket, road force varia-tion equipment is becoming in-creasingly popular as vehiclesensitivity to imbalance becomesever greater.

Steps for Balancing aTire/Wheel Assembly

Depending on the equipmentyou have, tire/wheel assembliesare balanced in a number of ways.The steps are outlined as follows ifyou are using one of the more mod-ern, automated machines, like theCoats 1250. These instructions arenot meant to cover every balancingsituation.

Before a tire can be balanced, itmust be concentrically seated. You

can determine this by measuringthe distance between the moldedrib on the lower sidewall of the tireand the edge of the wheel’s rimflange. The tire must be deflatedand reseated if the distance be-tween the two points is greaterthan 2/32-inch.

After ensuring that the beadshave reseated properly, the tireshould be inflated to the recom-mended pressure.

1. Turn your machine OFF thenON, which resets the balancer. Themachine wakes up using standardclip-on wheel weight locations.

2. Remove stones/rocks or otherdebris from tread and any weightsalready attached to the wheel.During this process you alsoshould remove any mud, dirt orsnow on the inside of the wheeland make sure that the mountingsurface of the wheel is completely

clean of debris.

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Today’s balancers can handle almostany car or light truck assembly that rolls into a bay in a quick and efficient manner.

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Cleaning the wheel prior to balancing is important.

3. Mount a tire/wheel assembly ona balancer that will use standardclip-on wheel weights. Use themost appropriate mounting meth -od. Technicians should be carefulto avoid back injury and shouldseek assistance when lifting aheavy tire/wheel assembly onto abalancing shaft.

4. There are three main mountingmethods. They include:• Back Cone – Most original equip-ment and steel wheels can bemounted properly using thismethod. The wheel is centered ona cone from the inner side of thewheel.

• Front Cone – A wheel should becentered by the outer side of thehub only when the inner surfacewill not provide an accurate sur-

face to center on.• Pin-Plate – An alternate methodof securing and aligning an assem-bly on a balancing machine is thepin-plate method. A pin-plate is

added instead of a pressure cup.5. Enter A & D wheel dimensionsusing offset arm.Before a wheel can be balanced,

wheel dimensions must be enteredinto the computer on your unit.These include: A = Offset – The distance meas-ured from the balancer (“0” on off-set arm) to inner plane of thewheel rim (inner weight location).W = Width – The width of thewheel at the rim flanges, measured

26 November 2012 | TireReview

The Back Cone method of mountingis most common.

There are a variety of pin-plates.These are just a few of the many thatare designed for the different sizesof bolt-hole chamfers and sizes.

Rapid Response: 800-928-1184 ext. 44026

Front Cone mounting is one alternate method.

The Pin-Plate method is a variationof the Back Cone method using a pin-plate.

with calipers.D = Diameter – The diameter of

the wheel as indicated on the tire.6. For automatic measurement,pull the offset arm out to thewheel, hold it still at clip-onweight position against the wheelflange and wait for a “beep.” Re-

turn the arm to home position.7. Enter the wheel width dimen-sion. Use plastic calipers to meas-ure wheel width for manual entry.Press the W key. Use the keypad toenter width value (between 2 and20 inches.) Lower the hood for au-tomatic measurement (see above).Note the value entry of the W dimension.

8. Lower the hood. The wheel willspin and unbalances are measuredand displayed. The correctiveweight amount appears in theweight display window for inboard

and outboard weight locations.9. Raise the hood after the tirestops rotating. Make sure that thewheel has stopped before raisingthe hood.

10. Inboard center bar blinks. Ifan inboard corrective weight isnot required, the wheel will stopat the outboard corrective weightlocation and you can go to Step13.

11. Attach inboard correctiveweight. Attach specified weightamount at top-dead-center on theinside flange of the wheel. NOTE:Wheel weight suppliers often willsupply a rim flange contour gaugeto help technicians select the cor-rect clip-on weight for the wheel.

12. Press NEXT, causing thewheel to rotate.

13. The outboard center bar willblink.

14. Attach outboard correctiveweights. Attach specified weightamount at the top-dead-center onthe outside flange of the wheel.

15. Lower the hood to respin thetire/wheel and check balance. Theweight readings should now be0.00.

Balancing In A NutshellThe balancing steps outlined in

this article are typical but will varysomewhat depending on the type ofequipment used.

Recapping the steps, a technicianmust:

1. Turn on the balancer2. Clean the tire, rim flangeand wheel3. Mount the tire/wheel assem-bly on a balancer4. Enter the A & D wheel di-mensions5. Enter width wheel dimen-sions6. Lower the hood to spin thewheel and check dimensions7. Raise the hood after the tirestops rotating8. Note when the inboard cen-ter bar blinks9. Attach inboard correctiveweight10. Press NEXT, which rotatesthe wheel11. Note when the outboardcenter bar blinks12. Attach outboard correctiveweights13. Lower the hood to respin

28 November 2012 | TireReview

Measuring the rim flange ensuresselection of the proper clip-onweight.

Note the clip-on weight location onthe wheel flange.

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A view of the pressure monitoringsensor being placed on the rim of thewheel.

Screen on a typical balancer prior tolowering the hood for automaticmeasurement.

Screens with newer balancers show inboard and outboard measurements automatically.

A, W and D dimensions on assembly.

and check balance

DisclaimerTire/wheel balancing is a

serious business. The preced-ing article was researched andwritten using material fur-nished by Hennessy Indus-tries, including photos anddiagrams. This information isNOT meant as a substitute forproper training by TIA, bal-ancing equipment manufactur-ers or tire manufacturers.

The balancing recommen-dations made here are consis-tent with practices used in theindustry when operating thistype of balancing equipment.This article is meant purelyfor educational purposes andthose who use the methodsrecommended are solely re-sponsible for any injuries orlosses resulting from their ap-plication. �

TireReview.com 29Rapid Response: 800-928-1184 ext. 44029

Just as there are a number of as-sembly balancing methods, thereare a variety of weights for balanc-ing purposes. There are standardclip-on weights of various typesthat are made to accommodate thecontours of different rim flanges. There are MC weights used on a

number of U.S. vehicles, ENweights used on VW and Honda ve-hicles, FN weights for Japanese ve-hicles and IAW weights used onmany South Korean and Europeanvehicles. A few of these types areshown in this box. There also are adhesive weights

that are not covered in this article.They are used for custom wheels orthose that do not have an outsideflange. Additionally, there are three pri-

mary materials used to producewheel weights. Lead weights, theoriginal weights used to balanceassemblies, are making their wayout of the scene. Several stateshave outlawed lead weights – ashave the European Union andJapan – and the EPA is consideringnational action. Remaining alterna-tives for both clip-style and stick-on weights include zinc and steel.

Standard clip-on weight

Clip-on mass weight FN weights used onJapanese vehicles

A Look at Wheel Weights