Custom wheel torquing 101
How to achieve the perfect torque in five easy steps, plus the five most common mistakes to avoid
by Mike Manges – http://www.moderntiredealer.com/channel/performance/article/story/2009/04/custom-wheel-torquing-101.aspx
The importance of following proper torquing procedures cannot be overstated, especially when working with expensive — and sometimes delicate — custom wheels.
“Custom wheels pose their own unique set of challenges,” says Sam Ortolani, national sales manager for Norbar Torque Tools and a recognized torque expert.
“One, they’re big, which makes them heavy. They’re aftermarket, which makes them much different than the wheels that came on your car.
“Original equipment wheels are designed to fit that car’s hub; aftermarket wheels are designed to fit a wide range of hubs. Because of that, they require hardware to make sure they seat properly on the center of the hub. And they may or may not need spacers.”
Knowing and practicing correct custom wheel torquing techniques will ensure proper performance, cosmetic satisfaction and most importantly, safe operation.
“The liability involved with a wheel-off is staggering,” says Ortolani. “Million-dollar claims are not unheard of.”
Here’s a look at how to achieve perfect torque in five easy steps.
1. Inspect everything before starting. The first step in the process is making sure the aftermarket wheel is structurally whole and functional. “You need to inspect the wheel thoroughly.
“You also need to make sure that all of the correct adapting hardware is in place and functional.” This applies to dust covers, which while pleasing to the eye, can be impractical. “Anytime you put something between the mating surface of the wheel and the hub, you increase your risk of a wheel coming loose.”
Check that the aftermarket lug nuts you’ll be installing actually fit the lugs and “that they go deep enough to secure the tire to the hub. It all has to be lined up before you do any work.”
Do not, under any circumstance, drill extra holes into the wheel. Anytime you physically modify a wheel “its structural integrity has changed.”
2. Clean mating surfaces properly. This means “no dust, no debris and no rust,” according to Ortolani. “You also have to make sure nothing’s hanging there that has the potential of affecting the clamp or vibrating itself loose over time.”
Norbar recommends using a wire brush to clean all areas that physically mate. “The whole wheel surface doesn’t touch the hub, but those parts of the wheel that do touch the hub need to be cleaned.”
Use an approved cleaning fluid if you want, but avoid anything that contains a lubricant.“When you lubricate a stud, you change the properties of that stud. It no longer torques the way it was intended.”
Another tip: Make sure your hands are clean. “If you have grease and oil on your hands from the brake job you just did, that oil will transfer from your hands to that surface.”
3. Mount the wheel and pre-torque it. At the pre-torque stage, Ortolani recommends using a limited torque gun. “Fifty or 60 foot-pounds is probably a good range. You just want to get the wheel on there snugly.”
Don’t forget to follow the traditional star pattern. And make sure your equipment is always under control. “You can pre-torque by hand up to a point, but we recommend that you use a tool, which will be consistent from point to point.”
He explains you will know when you have a good, snug fit “when all of the hardware looks even and there’s no looseness or wobble in the wheel. At this point, you have to brace the wheel” to prepare it for final torque.
“We don’t recommend that you completely lower the car and put all of its weight on the wheel. You can lower it down to a point where the wheel is now locked in place” using wheel chocks. The idea is to prevent the wheel from rotating during final torque.
4. Apply final torque. First, set the torque wrench to the recommended specifications provided by the wheel and vehicle manufacturers. “An F-150 wheel is torqued to a different level than the wheel of a Chevy Cobalt. You will always be safe if you use the manufacturer’s recommendation.”
Again, follow the star pattern when torquing. Resist the temptation to torque more tightly than necessary. Ortolani suggests having a “specific pattern and procedure you follow as you go around the car so that all of the wheels are done exactly the same.”
5. Customer follow-up. At this stage, many dealers take payment and return the vehicle to the customer. Smart dealers will use this opportunity to suggest the customer bring his or her vehicle back for re-torquing after 100 miles. “Those lug nuts will seat.”
This also gives you an opportunity to build your reputation as a torque expert. “A lot of tire shops say, ‘We’re going to get you in and out of here before you have a chance to finish your cup of coffee.’” You don’t want to be known as the fastest shop on the block, according to Ortolani. It’s better to be known as the safest and most thorough.
Mistakes to avoid
Due to the wide range of aftermarket wheels available, there are more opportunities to make critical — and extremely costly — mistakes during the torquing process. This also applies to the torque equipment you’re using. Here are five common mistakes to avoid:
1. Over-torquing, which is “a huge problem,” according to Ortolani. “All bolts have a yield level. Torque is a precision, controlled stretch beneath that yield. Once a bolt stretches past its yield, it no longer relaxes. Think of a rubber band. When you over-torque, you stretch a bolt beyond its yield.”
Bolts that are over-stretched don’t give a warning before they fail: they just snap. The best way to avoid over-torquing is to use precision calibrated tools, he says.
2. Pushing it just a little too far. Many techs, after following all of the proper procedures, succumb to the temptation of giving the wrench just one more click at the end of the process. “That’s very common; you see it very frequently… that little extra push. You’ve just defeated the purpose of your wrench.”
Have faith in your equipment, says Ortolani. “When it clicks for the final time, trust it.”
3. Improper torque wrench storage. Before you store your wrench at the end of the day, dial its setting down to the lowest level. This keeps the strain and stress off the hardware inside the wrench’s body. Leaving the wrench at its working limit will shorten its lifespan.
Hang your wrench on the wall instead of laying it on a bench or shelf. Make sure the room is climate-controlled.
The next morning, “exercise” the wrench before you use it by clicking on it 15 or 20 times.
“At night when your wrench is hanging on the wall, the grease (inside of it) settles to the bottom, just like your car when the oil settles into the pan.
“When you start up your car, you have that initial moment where it’s metal on metal until the oil starts to circulate. It’s the same concept with your torque wrench.”
4. Under-equipping your shop. Buy torque wrenches that match the volume of your shop, says Ortolani. “If you have four bays and one wrench, that wrench is working its tail off. Maybe the right answer is one wrench per bay and maybe one or two back-up wrenches?”
If you have more wrenches than bays, rotate those wrenches so you’re not using the same ones every day. “This will keep the wear on your wrenches fairly balanced.”
5. User inconsistencies. Make sure your employees are properly trained and receive additional training as products evolve. “Procedure is always driven from top down. Everybody in your shop needs to know, ‘This is what we do when we mount a wheel.’ You have to be consistent.”
And don’t forget to use the correct terminology, says Ortolani. While this may seem like a minor point, referring to torque wrenches as torque wrenches — not impact wrenches or impact guns — will ensure a more professional environment and prevent damage to wheels.
“An impact wrench hammers the hardware. They’re great for breaking stuff loose, but they’re not the right tools for precision tightening.”