Tires are among the hardest-working components of wheeled equipment, whether haul trucks or skid steer loaders. As the components that support the weight of the entire machine, while also carrying heavy loads around a site, tires need proper maintenance and care to promote safety on any worksite.
“Well-maintained tires can equate to increased profits, thanks to increased uptime, productivity, safety and on-time completion,” says Steve White, Michelin’s Earthmover market segment manager.
Tire manufacturers recommend that fleet equipment managers implement tire maintenance programs, either among site personnel or with a partner tire dealer, to extend tire life and address potential safety hazards as they arise.
“A tire maintenance program utilizing checklists of important tire service elements with recording of key data is very beneficial,” says Sam Munsell, Yokohama’s off-the-road national account manager. “The tire maintenance program can expand into a comprehensive tire-tracking program that incorporates complete tire service life information, which can support tire-cost management decisions.”
Employing pressure and wheel-maintenance programs, tire rotation programs, retread programs, and tire recycle programs will ensure each tire is accounted for and the status of each tire is kept up to date.
Some site managers will overuse tires to the point of failure to save on costs, but the consequences of unsafe tire practices can cost more than routine maintenance, repairs and replacements.
“If proper tire maintenance is not a priority, an operator is virtually guaranteeing he will reduce the tire’s life, increase the likelihood of tire-related failures, reduce the machine’s productivity, and unnecessarily cost the company money,” says Terry Beach, Earthmover sales force tools manager for Michelin. “It just doesn’t make good business sense not to pay attention to such a large operational asset.”
Operating a tire past a safe point because of cost used to be a larger issue, but recent regulatory crackdowns from agencies such as the Occupational Safety and Health Administration and the Mine Safety and Health Administration have shifted priorities.
“A lot of our customers are leaning toward safety versus running a tire to destruction,” says Roger Best, senior off-the-road engineer with original equipment at Bridgestone. “But there isn’t a customer out there that I know of that doesn’t have a tire that they wear beyond its lifetime. There are still customers out there that do run their tires to destruction.”
That lifetime varies on a site-by-site basis, according to Best. Operating conditions determine the minimum amount of tread that is necessary for safe operation of a tire, and tires should be pulled when this limit has been reached. Pull points should be coordinated between the manufacturer, dealer and customer.
When tires reach their designated pull points, they can be sent for retreading, which is an economical alternative to complete tire replacement.
“In many cases, up to certain size tires, earthmover tires can be retreaded at least twice,” says Dave Green, off-the-road product manager for Titan. “That assists the operations with lowering their operating costs against the initial acquisition of the tire.”
For example, the average market price for a 27.00R49 tire is $15,000. If after 8,000 hours of operation, the remaining tread depth (RTD) is 15/32-inch, the tire can be retreaded for approximately $7,000 and
experience a second life of about 7,000 hours. The total operating cost for this tire is about $1.47 per hour.
If that same tire is run to destruction, or 0 RTD, after 10,000 hours, the operating cost is approximately $1.50 per hour.
“In addition to the higher cost per hour, tire damage protection is decreasing and failure potential is increasing, which may risk vehicle damage or personal injury,” Munsell says.
The resulting costs from additional vehicle damage or employee injuries could be tremendous compared to those from keeping up with proper tire repairs or replacements.
Retreading depends on the tire casing, which is the most expensive part of the tire and is protected by the tread. Retreading should only occur if the casing has not been damaged or if the casing is likely to withstand the life of the retread. The equipment manager should work with the service provider to determine the best course of action.
Ultimately, following best practices and proper maintenance techniques can help a company promote safety in the workplace and prevent costly accidents.
“Anything you can do to draw more attention to safety,” Green says, “the better off we all are.”
Choose the correct tire
Manufacturers and dealers can help users choose the correct tire for their application’s requirements. There are consequences to choosing a tire that is not equipped to handle a particular load weight or site conditions.
If the incorrect weight is placed on a tire ill-equipped to handle such a load, then fuel efficiency, vehicle performance, and operator comfort could all be compromised, leading to additional maintenance costs.
“Often companies and operators seem to like to push their equipment to the limit, but they need to remember that load, speed and distance affect tire life,” White says. “Make sure the equipment and tires match your needs to operate more productively and safely.”
If the machine or site conditions change, equipment managers must re-evaluate tire specifications. Larger buckets, sideboard additions, or other machine enhancements that add weight to the machine can potentially overload the tires’ load capacity and pressure requirements.
Operating a machine in water can also be detrimental to the equipment’s tires.
“When you operate in water, you obviously have the visual problem of not seeing what you’re running over,” says Green. “Also, wet rubber cuts 10 times easier than dry rubber, so you’re setting yourself up for additional cuts and injuries to the tires.”
Of course, maintaining proper inflation pressure also optimizes performance and safety.
According to Beach, a tire that is underinflated by 10 percent can lose 15 percent of its life. A tire can lose 50 percent of its life if it is overinflated by 30 percent.
“Proper inflation will allow the tire to act as an efficient suspension component,” Beach says. “This will help prevent wear and tear on the equipment and the operator.”
Pressure checks are often overlooked on job sites, but a weekly pressure check program will uncover problems and enable them to be solved more efficiently. Beach contrasts this with engine oil checks, which usually occur daily due to the potential cost of an engine overhaul.
“What many equipment managers do not think about is that it costs almost as much to replace a set of tires that are destroyed because of inflation issues as it does to rebuild an engine,” Beach says.
If pressure needs to be adjusted, safe practices must be used when inflating or deflating tires. If a tire is not installed on a vehicle, it should be placed in a safety cage or otherwise restrained before inflation. Munsell recommends using an inflation hose that is long enough to allow the user to stand to the side of the tire during inflation, rather than in front of or behind it.
Perform regular tire inspections
Most safety issues, tire-related or otherwise, can be prevented if care is taken to inspect the machine and the site before and after every shift.
“The walk-around is not just for tires. It’s everything,” Best says. “You don’t know what the previous person did or didn’t even know they did.”
Machines should be inspected for abnormalities in the tires and rims. On tires, operators should look for punctures, indications of internal separation, irregular tread wear, under-inflation, or any exposed inner material. Rims that are bent, dented or cracked are considered unsafe to operate on and can lead to loose tires and weak spots in the wheel. Additionally, clearing the wheel components of caked-on mud and debris can uncover any potential damage that may have occurred during operation.
Green recommends operators follow a three-step process he refers to as, “Inspect, detect and correct.”
“You’re going to inspect your tires and look for anything that’s of concern,” Green says. “If you come across [a safety concern], you’re going to detect it, identify what it is, and then take corrective measures.” Those measures typically involve informing site management of the issue so the necessary steps can be taken for repair or replacement.