Aluminum Wheels, Replace or Repair?

Purpose

This bulletin will provide information concerning the restoration and reuse of damaged aluminum alloy wheels. Collision repair shops and insurance damage appraisers need to be aware of what types of damage are repairable and which damage should not be repaired. We will also identify important aspects of the restoration process and the equipment or technology necessary to accomplish a quality repair.

Introduction

As automobile designs become more aerodynamic and vehicle styling presents a greater image statement for the driver, tire and wheel designs have also changed. Stylish aluminum alloy wheels are becoming more popular than ever. Most of these wheels are manufactured by casting the aluminum alloy into the desired wheel shape, then machining it to precise design specifications. Special coatings or plating treatments are applied to these aluminum alloy wheels to achieve the desired appearance and corrosion protection.

One disadvantage of these stylish wheels is the high replacement cost, when only minor damage has occurred. Frequently encountered damage may include surface abrasions, corrosion and a damaged tire retaining lip (such as scrapes, a bent lip, and a cracked or broken off piece of the rim lip). Typical original equipment alloy wheel replacement cost will be $300-$600 or more for special models or custom designs. The increased volume of usage and high replacement cost, combined with low profile tires rolling over pot holes or other road hazards, has identified a market need for repairing these damaged wheels when appropriate.

Wheel restoration shops have opened in the past few years to provide this service as a cost effective option to replacing alloy wheels that have cosmetic or minor damage. Wheels can frequently be repaired for 20-40% of the replacement cost, depending on wheel type, cost and extent of damage.

Until recently, aluminum alloy wheel were generally thought of as non-repairable items, however this is not the case. Cast aluminum and many related alloys are repairable, but must be done correctly. To achieve quality repairs, a repair facility must have knowledgeable technicians and the proper equipment for straightening, welding and refinishing alloy wheels. There has been a limited understanding of this type repair, as well as a limited number of businesses which have the proper staff and equipment to provide high quality repairs. As the percentage of vehicles with aluminum alloy wheels increases each year, more businesses will be providing wheel restoration services.

Repair or Replace the Damaged Wheel?

The option to repair a damaged wheel should be considered only when the damage is cosmetic or confined to the tire retaining lip area of the wheel. Photographs 1 and 2 are two examples of repairable damage.

Depending on the replacement cost and the location or extent of damage, some steel wheels may also be repairable, by the same repair facility.

The damaged wheel must be replaced if there are fractures or obvious deformation in the center hub or support structure of the wheel. A close inspection should be made in both areas from the front and back side of the wheel. Particular attention should be given to deep scratches, since they may actually be fractures which could lead to wheel failure. If only cosmetic damage is evident in these areas, the wheel may be repairable.

When either the collision repair shop or an insurance damage appraiser determines that a wheel appears to be repairable, it is sent to a qualified wheel restoration shop. The wheel restoration shop will inspect and test the wheel to determine if the wheel is repairable. If a damaged wheel is beyond repair and must be replaced, several options are available: a new O.E.M. wheel, a used "Like Kind and Quality" (LKQ) wheel, or another repaired wheel from the wheel restoration shop.

Some wheel restoration facilities offer a wheel locator service free of charge or they may have a stock of common wheels, they have repaired, which are for sale. A larger facility may have a wheel exchange program where they will send you a repaired wheel with an additional core charge; then you return your damaged wheel in the same carton. If the returned wheel is repairable, the core charge is refunded.

The Aluminum Wheel Restoration Process

After a damaged wheel is received for repair at a qualified wheel restoration shop, the following steps will outline a quality wheel restoration process:

1. Identify the year, make and model of vehicle the wheel is from.

2. Clean and inspect the wheel.

3. Measure the wheel for lateral runout (wobble side to side) and radial runout (vertical high or low spots along the wheel's diameter), while rotating on its hub.

4. Determine the severity of damage to the wheel, is there surface damage or is the wheel material itself damaged? Then identify the appropriate repair procedures necessary to restore the wheel.

5. Using a combination of heat and pressure, bent wheel lips are straightened. Caution! Alloy materials should not be "beat back into shape" with a hammer, since doing so can create invisible stress fractures.

6. The wheel's material alloy is identified. This is necessary: to perform weld repairs to the wheel material, to select the proper welding filler rod, and to help match the original alloy color. The repair shop should also be knowledgeable about the reparability of these wheels, based on the wheel material and configuration.

7. The wheel material is repaired by filling in gouges or missing areas using a Tungsten Inert Gas (TIG) welder and the correct filler rod. Currently, TIG welding is the only approved procedure for repairing damaged material on aluminum alloy wheels. After welding, the repaired area is ground close to the desired shape.

8. A lathe should be used (a final machining operation) to obtain the specific dimensional shape of the wheel lip. This operation will also remove small amounts of lateral and radial runout to within a .010-.015 inch (.25-.38 mm) tolerance, to assure the wheel is "true" (round and concentric), while rotating about its mounting hub.

9. The repaired wheel is then polished and the original finish is re-established by applying the appropriate coatings or plating treatments to the wheel. Photographs 3 and 4 are two repaired examples of the damaged wheels previously shown in Photographs 1 and 2 above, respectively.

Identifying A Qualified Wheel Repair Facility

The following guidelines should be used to help identify a qualified wheel restoration facility, one that is properly equipped to perform a quality wheel repair.

Equipment to mount a wheel, rotate it about the hub axis and accurately measure both lateral and radial runout to determine how "true" the wheel is.

Machines to selectively apply steady, non-impacting pressure and heat to wheels for straightening bent tire retaining lips. They MUST NOT depend on a hammer or other impacting techniques to straighten bent rim lips, as it may cause internal stress cracks and the wheel could fracture while in use.

The repair facility MUST have the proper Tungsten Inert Gas (TIG) welding equipment with a selection of filler rods. A certified and experienced welding technician performing the welding operations is also essential. The correct equipment and operator is required, since TIG welding is the only approved procedure for repairing damaged material on aluminum alloy wheels.

Test equipment or manufacturer's data is needed to determine the specific type of aluminum alloy the wheel is made from. The wheel material type is used to select the correct welding rod, to achieve a quality weld, when repairing damaged or missing wheel material. The correct welding rod is also needed for the weld color to closely match the original material. Material color match is very important when the wheel's finish coating is clear.

A lathe and other machining equipment to re-machine the repaired areas of the wheel to obtain the desired lateral and radial specifications of the rim lip, in relation to the center hub's rotation axis. This is to ensure the wheel is "trued" and dimensionally correct.

The wheel cosmetic finishing area for polishing and coating the repaired wheel should have the ability to apply the necessary coatings to restore the original finish and operate within current E.P.A. regulations. Some finishing operations may be sublet out to specialty plating companies, since it may not be practical to do all operations in house, such as anodizing, chrome and gold plating.

In general, evaluate the facility for a professionally run, high quality operation, since the vehicle owner will depend on the quality of work performed for some time. Establishing a working relationship with one wheel restoration facility can aid in providing consistent, high quality, cost effective source for repairing damaged aluminum alloy wheels. This may have a significant impact on minimizing repair costs. Also, ask the wheel restoration facility if they have a wheel exchange program, where you can return to damaged wheel "core" after receiving a restored wheel to reduce vehicle down time.

The information provided in this bulletin is for educational purposes only. Although every effort has been made to ensure the accuracy of the information contained in this bulletin, Tech-Cor assumes no responsibility or liability for any repairs performed using information from any publication issued by Tech-Cor.

Any person performing repairs must determine whether any suggested or recommended procedures or repairs are suitable or appropriate for the particular vehicle being repaired. The repairer remains solely responsible for such determination, as well as for the proper completion of the repairs.

Reproduction of this bulletin is not permitted without the written approval of Tech-Cor.