The transportation industry is certainly in a state of transition. Trucks, buses, tractors and trailers are all being designed for improved fuel economy, automation and range.
As a result, tires are being designed specifically for the types of operations and vehicles they are destined for as well as improved fuel economy, and wheels are produced with fuel economy, loads-carrying capacity, maintenance and appearance in mind.
Since the push for greater fuel economy is one of the main forces driving the trucking industry, commercial fleets have been transitioning to aluminum wheels because they are lighter (about 1,200 pounds on an 18-wheeler) than steel wheels.
Lighter vehicles improve rolling resistance and reduce fuel consumption. Since the 1980s when freight carriers first started using aluminum wheels, their adoption has grown. By 2000, aluminum wheels accounted for 50 percent of the market.
Today, their share has grown to about 65 percent. This growth will continue as electric vehicles — which require lighter components in order to increase their range on a single charge — and diesel- and other alternate fuel-powered vehicles strive for better fuel economy.
Since aluminum wheels also improve the aesthetics of vehicles and help make them look shiny and bright, they are a factor that attracts and retains drivers in an industry suffering from a driver shortage.
So in all likelihood, you are going to have a growing customer base looking for help in making these wheels look good.
Aluminum wheels do require maintenance. They oxidize, experience rim flange wear and can be damaged by heat from dragging brakes, frozen bearings and from running on flat tires.
Their shiny surfaces can become dull due to road dirt and other contaminants, and they must be polished frequently to keep them glistening. Since their appearance is a big attraction for many truck operators but constant maintenance is not, aluminum wheel manufacturers have developed coatings for these wheels that eliminate the need to polish them.
These wheels never should be polished since that will effectively remove the coating. Therefore, it is important to first know the difference between a polished aluminum wheel and a coated aluminum wheel, and second, the procedures for properly cleaning them.
The first thing to do is locate the manufacturer identifying marks on the wheel. If these marks are not legible, the wheel should be removed from service since they are required by Federal Motor Vehicle Safety Standard (FMVSS) 120 to be on all wheels operating on U.S. roads.
These marks are usually found on or near the DOT stamp on the wheel.
Arconic Inc. (formerly Alcoa Inc.) applies a Dura-Bright decal on coated rims and puts its wheel part number followed by DB (for Dura-Bright) to indicate the wheel is coated.
Accuride Corp.'s coating is called Accu-Shield. Wheels with this coating are identified by Accu-Shield decals on the rims and the stamped manufacturer information that is followed by SPC (Standard Polish and Coating) or XPC (Extra Polish and Coating) in a triangular shield pattern.
If these nomenclatures are not found, the wheel is a polished wheel.
Then inspect the wheel thoroughly for any damage or out-of-service conditions.
Some aluminum wheels come with a heat sticker installed on them. If the heat sticker indicates the wheel has experienced excessive heat or the wheel shows other signs such as discoloration, charring, cracking, brittle or distorted areas in the bead seat area, the wheel should be placed out of service.
If the tire is removed from the wheel, check the rim flange area for wear with a rim flange wear gauge. Any wheel that is rejected should be marked and tagged unserviceable and scrapped.
Next, no matter what type of aluminum wheel you are working with, it needs to be cool to the touch (95° F / 35°C) before you do a pre-wash. So let the wheels sit and cool off if they are on a vehicle that just drove in to your shop.
Then rinse the wheels with a hose or a pressure washer to spray the surface of the wheels and around the stud holes. If the tire is still mounted on the wheel, exercise caution when using a pressure washer to prevent tire damage with an excessively strong stream of water.
After a wheel has been rinsed off and the big chunks of loose dirt and debris have been removed, use one of the many aluminum wheel cleaners on the market that loosen dirt, grease, grime and brake dust that has collected on the wheels.
Do not use strong detergents, alkaline or acidic cleaners to clean an aluminum wheel. These solutions can etch the surface of the aluminum and leave dull areas. Prior to applying cleaning chemicals verify the wheel is at ambient temperature.
Apply cleaner over the surface of the wheels, inside the hand holes and around the stud holes. Agitate the cleaner with a soft-bristle brush (not a wire brush) periodically while applying water. Scrub the surface of the wheels inside the hand holes and stud holes.
If the tire is removed, scrub the wheel drop center with all-purpose cleaner and a stiff-bristle brush.
Then rinse the wheels with a hose or a pressure washer. Repeat this process if necessary.
Failure to perform this cleaning step may have a negative effect on polishing performance and the wheel's final appearance since rubbing debris against the surface of the wheel can scratch the wheel.
There are several ways that aluminum wheels can be polished. The first is by hand.
After the wheel has been pre-washed and has dried, use a non-abrasive aluminum polish on the wheel. This can be applied by hand and requires a lot of rubbing with a soft, clean, microfiber towel.
Be sure to follow the instructions on the polish. Most should not be allowed to dry on the wheel. To prevent the polish from drying, polish one section of the wheel at a time. It can take 20 to 30 minutes to polish one wheel this way.
The second is using power tools. After the wheel has been pre-washed, use a non-abrasive aluminum polish on the wheel and a soft bristled wheel pad to polish the wheel. This cuts polishing time in half.
There is also a portable wheel-polishing machine available on the market that you can roll right up to the truck and have the machine polish the wheel which takes about 15 minutes. It polishes the wheel but does not remove any oxidation on it.
The third is to machine-polish aluminum wheels. If you already are refinishing steel wheels in your retread plant or service facility, you may want to consider getting a robotic, aluminum wheel-polishing cell as well if you haven't done so already.
Tires do not have to be demounted before putting wheels into these machines. But if they are, aluminum wheels are completely refurbished and restored. Oxidation is sanded off and the wheels are buffed to a shiny finish in 30-60 minutes. There is very little operator involvement required.
During high-speed polishing, wheels can experience bolt-hole washout. This condition can be seen on the polished side of the wheel.
Check the wheel's non-polished side to see if bolt holes or hand holes are washed out or wallowed out. This condition is not an out-of-service condition that requires the wheel to be removed from service, but it isn't pretty.
Accuride recommends that once wheels are polished, carnauba wax be used to protect the polished wheel surfaces, help prevent corrosion and pitting caused by natural environmental contamination and to make future cleaning and polishing easier.
Otherwise it warns the polished surface will be susceptible to water spotting and/or pitting from environmental contaminants. If you do apply carnauba wax, use a clean, dry, cotton cloth to remove any excess wax.
Cleaning protective coated aluminum wheels
While aluminum wheels with protective coatings are not to be polished, it may still be necessary to clean them in order to restore their shine.
To clean coated wheels after they have cooled to the touch (95° F), use a hose or a power washer to rinse them thoroughly to remove as much loose, visible dirt, sand and other debris as possible. This helps prevent scratching and abrasion during the cleaning process.
Once again, if the tire is still mounted on the wheel, exercise caution when using a pressure washer to prevent tire damage with an excessively strong stream of water.
Then generously apply a mild detergent such as automotive car wash soap or common dish detergent to the wheel surface with either a spray applicator, a 100-percent cotton cloth or a clean soft bristled brush or sponge.
To prevent etching or staining of aluminum due to the use of improper cleaning solution, use only a non-corrosive, aluminum-appropriate, clear coat, safe cleaning solution. Never use cleaning products containing hydrofluoric acid or abrasive tools and scouring pads (such as 3M Scotch-Brite) since they will remove the protective coating. Do not allow the soap to dry on the surface of the wheel.
Finally rinse the wheel thoroughly with clean water to remove all remaining soap and dirt. If you want to dry the wheel, be sure to use a soft, clean cloth.
Do not use polishes or wax on coated aluminum wheels. Their finishes will maintain a bright and shiny surface for many years without the need for special polishes.
After polishing or cleaning any aluminum wheel, inspect the DOT stamp again to ensure it is legible. If the heat sticker is removed from the wheel, you can replace it with aftermarket heat indicators that turn colors when wheel temperatures rise above 250 degrees.
Like the trucking industry, the truck wheel industry is also transitioning. Aluminum wheel polishing and cleaning eventually will eclipse steel wheel refurbishing as aluminum wheels continue to take over the market.
Use this opportunity to offer polishing and cleaning services to your commercial fleet customers that will provide a new revenue stream for your business if you haven't already done so.
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