Wheel installation 101: Basics to prevent wheel separations and a lifetime of regret

Key takeaways:

• Wheel separations are an all-too-common occurrence that often stems from improper maintenance
• Following OEM guidelines and the RIST method helps achieve proper clamping force
  
• Verifying torque wrenches are calibrated and performing a road test helps ensure a safe wheel install

As an owner-operator working in Canada in the mid-1990s, Jim Park hadn’t cared much about the specifics of wheel installations. That was until two different fatal wheel-off events occurred in a span of a few months and he began speaking to truckers on behalf of the Ontario Trucking Association's Knights of the Road Team (the Canadian equivalent of the American Trucking Associations' America's Road Team).

They were emotionally charged discussions, Park, a regular contributor for Fleet Maintenance, recalled in a recent article for FleetOwner. The importance of following the correct wheel installation procedures to prevent wheel separation—including fastening the lug nuts to the proper torque level—was now acutely in the driver’s mind.

Consequently, he endured his own tense interaction—forever seared into his memory—with a “reputable” tire shop in Ontario.

It was a frosty February day in 1997, and Park observed that after a tire repair, the technician wasn’t following those critical procedures.

“I refused to sign the work order,” he wrote. “That set in motion an unpleasant confrontation between me and the tire guy, and eventually his boss and my boss. I demanded the wheel be removed and then properly installed, including the cleaning of the mounting surfaces and proper torquing of the fasteners, etc.”

If the fasteners are not tightened to the correct specification, road vibrations could eventually wriggle the nuts free from the hub, which in turn would allow the several-hundred-lb. tire to eject off the spindle and down the road at 60 mph (or for metric-system users, 100+ kilometers per hour).

Park knew if this were to occur as he was driving down the highway, it could mean instant death for one or more unlucky motorists in the wheel’s path. Not a great look for someone who publicly spoke about the dangers of wheel separations.

During this conflict, Park found the shop didn’t even own a calibrated torque wrench. This is a crucial error for any tire repair business. OEMs have very clear guidelines on what the torque spec needs to be for that specific type of wheel (steel or aluminum).

He found this negligence even more unbelievable given the previous “three years of very public handwringing over three fatal wheel separation incidents and the implementation of a training and certification program for wheel service technicians.”

Nearly 20 years later, Park notes that this type of malfeasance is still rampant across North America. Wheel-offs are unfortunately not tracked in any federal database (a crime itself in the age of data), and a serious investigation into the maintenance failure hasn’t been done since 1991, when the National Safety Board began a special investigation. But based on the reported number of wheel-offs, three to five wheel-offs happen every day in the U.S.

“The ones we hear about usually involve vehicle damage and often personal injury,” Park offered. “Occasionally, someone dies. Who knows how many we never hear about?”

Another question is that if more drivers were as proactive and outspoken as Park, would the issue be as prevalent?

Fleet Maintenance has written a lot about this topic and agrees that the U.S. needs to track all wheel-offs, even when no one was injured. It’s for the same reason why good safety managers track near-misses. Just because tragedy was averted this time doesn’t mean an organization shouldn’t treat it as a breakdown in process.

And near-misses are likely more common than estimated. In the middle of writing this piece, I visited a trailer repair shop and the first technician I talked to about it recalled a time early in his career that his oversight led to a dolly trailer wheel-off.

Luckily, no one was hurt, and years later, this tech (who we’ve decided to keep anonymous) affirmed he meticulously checks the spec sheet for torque values every time to never make that same mistake. He also has his own personal torque wrench that he routinely gets tested for proper calibration when the tool truck comes around.

He does this because he knows the possible alternative.

“I would probably think about it for the rest of my life, honestly, if I was responsible (for a wheel-off that hurt or killed someone),” he told me.

We don't want any tech or shop manager to have to face those consequences, so here are some basics that every wheel installer should know prior to working on the wheel end.

[Disclaimer: These are not the only things you should know, and you should always consult OEM and industry best practices.]

Leading causes of wheel separations

The report found the leading causes of wheel-offs were all due to improper maintenance, such as not catching bearing failures and improper tightening of fasteners.  Under-tightening can occur if you’re not using a torque wrench to meet the recommended measurement, or if that wrench is out of calibration.

Under-tightening of wheel fasteners by failing to follow recommended practices and/or not using a torque wrench

Park noted in the ‘90s Ontario decided to enforce stricter out-of-service guidelines for loose, missing, or damaged wheels and wheel fasteners, as well as making wheel-offs an "absolute liability offence" as opposed to a "strict liability offence." The province also enacted mandatory certifications for wheel installers.

These actions cut wheel separation events in Ontario by more than half, Park reported. The region also started more closely tracking wheel-offs to glean common root causes. A 2016 report found:

• Over 80% of wheel-off events were due to failed fasteners.
• 10-15% were from failed bearings
• The remaining percentage was due to cracked wheels, axle failures, etc.
• They happened most often in January and February
• When failed fasteners were the cause, 83% of the time the wheel had been removed for brake service

What shops can do to prevent wheel-offs

At a minimum, every tech who installs wheels should know the RIST method. (And if they don’t, they should write it on their wrist.) This acronym developed by the Tire Industry Association stands for:

R: Remove debris from mating surfaces.

I: Inspect components for damage or excessive wear.

S: Snug the fasteners in a star pattern.

T: Torque to specification.