Page 34 - Newcom

34 COVER STORY
Wheel separations back in the public spotlight
TRUCK NEWS
April 2016
Continued from page 1
arations.
“The engineering of the compo-
nents is adequate,” said Rolf Vander- Zwaag, manager, maintenance and technical issues with the Ontario Trucking Association (OTA). “There is no inherent weakness in any of this, so that leads to, if you put them on right, everything will perform as expected.”
VanderZwaag helped Ontario de- velop its mandatory Commercial Ve- hicle Wheel Service training program, which was introduced in the mid- 1990s following another series of high- profile and tragic wheel-offs. Today, Ontario is the only province that re- quires wheel installers to become cer- tified, though the program is widely used in other provinces as well.
“We’ve trained thousands and thou- sands of people,” VanderZwaag said.
mating surfaces and inspecting the components for signs of wear before they’re re-installed. It’s a job that can’t be rushed, he stressed.
“If the job takes 45 minutes, it takes 45 minutes,” he said. “I don’t care if dispatch is screaming for the truck
or operations are screaming for the truck, you have to do all the steps. It’s a complete system.”
Jim Wagner, sales manager with Bast Tire and Auto Service in Water- loo, Ont., added installers need to in- spect studs carefully between instal- lations – especially in applications where the wheels are frequently re- moved.
“It’s really hard for a person to be able to tell whether the stud has been stretched to the point where you have to replace it,” he acknowledged. “I deal a lot with the waste industry and be- cause they have so many flats on some of these trucks, they may have the wheel off and on one truck 12 times
in a year. Every time you’re torquing that thing down, you’re stretching that stud and at some point in time your stud is going to become very weak.”
as it moves and flexes and twists and so on, you may lose a bit of clamping force.”
Do most operators take the time
to stop for a retorque after 100 kilo- metres? Opinions on that vary wide- ly. Dale Holman, president of a small fleet called Tabcor Holdings and a cer- tified wheel installer, pointed out re- torquing has its limitations.
“Nobody gets their wheels retorqued unless they have a very strict com- pany policy and they have four tire companies within a radius of their shop, where they can pull in and get retorqued,” he said. “And if I’m a guy doing the retorque, how do I know
the first guy doesn’t have it torqued to 1,000 lb.-ft.? You can’t measure exces- sive torque without removing the nuts and then it starts the whole process all over again.”
McDonald agreed that, “The success or failure of the retorque is directly de- pendent on the original installation.
If the original installation was done improperly or they didn’t use lubrica- tion, you can retorque the thing until the cows come home. You’re going to get the right amount of torque but the wheel’s still going to be moving be- hind the nut because you don’t have the clamping force.”
Davies emphasized the importance of verifying the torque within 100 kms to ensure the installation was done correctly and the wheel is still secure. Fleets should have incentive to con- duct rechecks, since they’re required to maintain a full and complete vehi- cle maintenance file, which includes the name of the technician who did not only the wheel installation, but also the retorque.
“With no paper trail,” McDonald said, “they don’t have any of that.”
If an issue exists with a wheel instal- lation, drivers are the last line of de-
But Dave McDonald, commercial
sales manager with Bridgestone Com-
mercial Solutions, noted not all tech-
nicians have received sufficient train-
ing on wheel installations from their
technical schools. The biggest prob-
l“em he sees in the field is the installa- It’s also important to use quality
People believe it’s the torque that holds the wheel on the vehicle, but it’s not. It’s the clamping force.”
Dave McDonald, Bridgestone Commercial Solutions
This imminent wheel separation was recently prevented by MTO enforcement officers at the Whitby scales on Hwy. 401.
fence before a potentially catastrophic separation occurs on the road. They should be conducting thorough pre- trip inspections and looking for tell- tale signs of movement, such as rust streaks.
“That’s a sign of metal rubbing on metal,” McDonald explained. “It’s just metal filings that splay out from the wheel through the centrifugal force
of it driving down the road. Then, you get a little moisture in the air and the metal filings turn to rust and it turns into a rust streak. Anytime you get that type of thing emanating from the wheel nut, that’s a classic sign of an issue and you’re out of service right there.”
Wagner advised against placing caps over the studs, as they can con- ceal potential warning signs.
He also said drivers should give tires a good kick during their walk- around inspections to see if there’s
Continued on page 72
tion of wheels without lubrication. “A lot of people don’t understand
that the torque values in a hub-piloted wheel system are lubricated values,” McDonald explained. “If you don’t use the proper lubrication in combina- tion with a calibrated torque range... the torque you put on is not going to develop the necessary clamping force and the wheels can come loose. Just because the torque range says
475 lb.-ft. doesn’t mean you have the right amount of clamping force. Peo- ple believe it’s the torque that holds the wheel on the vehicle, but it’s not. It’s the clamping force.”
McDonald said wheel installers need to take a complete systems ap- proach to their work, noting how
each step in the process affects other components within the system. This means properly cleaning fasteners and
fasteners, which will be more resistant to fatigue.
“If you want to save money in your maintenance budget, this is not the place where you want to save 20 cents on a cheap offshore nut,” McDonald said. “You want to make sure you’re using top quality fasteners and top quality wheel-end products.”
When a wheel has been removed from and re-installed onto a truck or trailer, operators are required to stop to have those wheels retorqued 100 ki- lometres into their trip. Torque stick- ers should be placed on the unit to re- mind drivers to have this done.
“All the joints, as you put them to- gether, have what they call stack set- tling (between metal components),” Wagner explained. “Even if you torque it, let’s say there’s a little bit of dirt or oil or something between those stacks,
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