Installing a set of wheels and tires to any vehicle requires proper technique, but it’s even more important when dealing with expensive alloy wheels and performance tires, as the customer expects a premium installation. The stakes are elevated when the application involves a high-dollar performance vehicle.
Any customer should expect quality work, but performance enthusiasts’ expectations bring this to a higher level.
Here we’ve addressed five major areas of concern to make sure the job is properly handled.
1. Cleanliness. Take the time to make sure that all contact surfaces are clean and free of dirt, grit or other contaminants. This includes both the mating surfaces of the hub and wheel as well as the threaded fastener surfaces (studs and nuts or bolt threads and female hub threads).
Heavy contaminant or rust buildup between the hub and wheel will prevent a flush mounting surface, which can result in lateral runout.
Dirty or rusted threads can lead to inadequate torque value. Naturally, any galled or otherwise damaged threads, male or female, must be replaced.
2. Appearance. Considering the design of many aftermarket alloy wheels, the calipers and rotors will likely be visible. If the rotor hats and/or calipers are rusty, address this with the customer. Options may include scuffing, cleaning and painting the rotor hats with a high-temperature paint, or replacing the rotors with units that feature a rust-resistant coating.The same applies to calipers. Depending on the customer’s budget and wishes, replacing calipers with high-temp, powder-coated aftermarket performance calipers is always an option to consider.
A quick approach that cuts corners is unacceptable. Shop time is valuable, but when dealing with expensive performance wheels and tire packages, take the time to attend to the details.
Following installation, be sure to wipe any grease or fingerprints from the wheel surfaces.
3. Verify wheel fastener style. It is absolutely critical to install the fastener style required by the wheel. Never assume that the fasteners that may have been supplied with the new wheels are correct.
Inspect the wheels to see if they require a conical or radiused “ball” style fastener and make sure that the matching style of fastener is installed. Mismatching fastener seat style will absolutely cause inadequate clamping and will result in loosening during operation.
Verifying the correct fastener seat style is a critical safety factor. When closed nuts are being installed, make sure that the studs do not bottom out inside the nuts. Measure the exposed stud thread length and verify that the nut provides sufficient thread engagement without bottoming out. If the stud bottoms out in the nut, seat engagement and clamping load cannot be achieved.
4. Checking clearance. If the application involves a non-OE modification such as wheel offset or backspacing, and/or larger tire section width, test-fit prior to completing the job. Prior to tire mounting, test fit both front and rear wheels to verify that the wheels clear struts, springs, calipers, etc.
When checking front wheel positions, turn the steering wheel throughout its full lock-to-lock travel while checking clearance. After test mounting one tire, perform the same check with the vehicle raised and with the suspension loaded. Never assume that an upgraded package will provide needed clearance.5. Proper torque. Alloy wheels must be properly clamped to the hub, which involves applying the correct torque value and tightening in the correct pattern. Avoid power tools (this includes pneumatic or electric impact wrenches) and torque sticks. Use only a properly calibrated torque wrench.
Improperly tightening wheel fasteners, whether under or over torqued, can lead to fastener failure and/or distortion of the hub. A distorted hub will result in lateral runout and vibration. Take your time. Using an impact wrench can easily result in scratching or gouging of the wheel and marring/burring the wheel fastener.
Also, don’t simply grab any socket wrench that’s handy based only on size. First verify that the socket is clean and free of dirt and grit. Also, if the socket must enter a recess in the wheel in order to make full engagement of the fastener head, make sure that the socket fits into the recess without contacting the wheel. In some cases, a thin-wall socket will be required. Carefully verify the socket wrench size to make sure that it’s correct for the wheel nut or bolt. Close enough is not good enough. If the fastener requires a 19 mm socket, don’t use a metric or inch format socket that “is close enough.” Excess slop in fitment can easily mar the hex surfaces of the fastener. Naturally, if the fasteners are splined (“tuner” style), a specialty splined socket wrench is needed.
Most wheel fastener torque specifications are based on dry threads. Do not apply a low-friction lubricant to the threads such as anti-seize, etc., as this can easily result in over-torquing, which can compromise the strength of the stud.
However, when installing an alloy wheel onto a steel hub, it’s a good idea to apply a thin coat of anti-seize lubricant onto the hub face to eliminate potential electrolysis between dissimilar metals, which can make future wheel removal difficult.
Tighten in a pattern that will spread the clamping load evenly across the hub. In the case of a 5-bolt pattern, for instance, tighten the 12-o’clock position, followed by the 5-o’clock position, followed by the 10-o’clock position, followed by the 2-o’clock position, followed by the 7-o’clock position. Instead of applying full torque at each location, apply an initial torque in order to settle the wheel flush to the hub, followed by a second torquing at the desired value. For example, if the specification calls for a torque value of 75 ft.-lbs., apply 30 ft.-lbs. during the first tightening phase, followed by 75 ft.-lbs. at the final phase. Paying attention to wheel clamping load will help to ensure an evenly distributed load across the bolt circle.
The best way to tighten wheel fasteners is with the vehicle raised to remove suspension load. Have a helper apply the brakes while you tighten and torque to value. This eliminates trying to overcome load on the wheel and hub as you tighten. If you are alone and insist on torquing with the vehicle on the ground, first tighten by hand while the suspension is unloaded while holding the wheel and tire by hand. This will allow you to apply perhaps 30-40 ft.-lbs. of torque. Then lower the vehicle until the tires touch the shop floor with enough grab to prevent wheel rotation before applying final and full torque value.
Trying to tighten with full vehicle weight on the suspension can result in unevenly applied or insufficient torque load, since you’re applying partial torque in order to mate the wheel flush to the hub.
Especially when dealing with new alloy wheels, do not rely on the initially applied full fastener torque for long-term use. After driving the vehicle for approximately 50 miles or so, the fasteners should be loosened, and then properly re-torqued. This addresses any potential alloy compression that may occur during the first driving cycle.
Again, avoid the use of power tools. Loosen and tighten using hand tools, tightening only with a calibrated torque wrench.
(As a convenience, make sure the customer knows what socket wrench to use when tightening the wheel fasteners, whether that involves a thin-wall socket or a splined socket. In the event the customer needs to service a wheel after the vehicle leaves the shop, that gesture will at least make sure he or she will have the correct wrench at hand.)
Installing custom wheels takes time. The vehicle is not at a race track where seconds count. It’s in your shop, so there is no reason to rush the process. ■