The right tires are essential for ensuring optimal fleet performance, which is why staying on top of service is so important for fleet managers.
The optimal tires for waste hauling fleets can cost anywhere from $500 to more than $1,000 each, so regular maintenance is critical not only for maximizing uptime, but also for keeping costs low.
Fortunately, fleet managers can conduct much of the maintenance needed in-house by establishing a formal tire management program, tracking the right data and knowing when to retread a tire or when to replace it with a new one.
Choosing the right tire
Selecting the proper tire at the outset is critical for starting off a tire maintenance program on the right note. Waste hauling fleets are tasked with navigating a variety of conditions, so finding one that can resist the everyday wear and tear of the road is a must for mitigating damage.
Nick Davis, a senior product marketing manager for Goodyear, based in Akron, Ohio, says most fleet managers look for three primary things when choosing the tires for their fleets: durable and retreadable casings, ample traction requirements, and treadwear that provides the most hours before removal.
“Treads play a vital role in a tire. They are designed to provide traction and protect the underlying tire casing so it can be retreaded,” Davis says. “Irregular wear signals an issue with tire or vehicle maintenance and should be addressed promptly.”
Casings are a layer of crisscrossing threads beneath the tire tread and are rated by the number of threads per inch (TPI). Tires with a lower TPI resist wear better, while tires with higher TPI typically weigh less.
Tires with wide treads, deep tread depths and a high net-to-gross tread pattern yield the best results for long-lasting treadwear, Davis says. High net-to-gross tread patterns have more open tread patterns, which gives tires improved traction.
In general, two tread designs exist: rib designs and lug designs. Rib tread designs, which consist of a series of parallel zig-zagged grooves, generally have shallower treads, less traction and better wear rate. Lug designs, which consist of parallel and perpendicular lines forming blocky shapes, have better traction but tend to wear quicker and have inferior fuel efficiency compared with rib designs.
Because refuse trucks face a variety of conditions, which to choose depends primarily on one’s traction needs.
“Fleet managers should evaluate the traction they need from their tires. Depending on the routes those tires are running, they may want to opt for a lug design over a rib design,” Davis says. “For example, fleets that primarily operate in suburban neighborhoods with paved, even roads may benefit from a tire with a rib design, while trucks that frequently navigate through water, mud, dirt or snow might see better performance from tires with lug treads.”
Once the right tires are selected, fleet managers can take steps to assure the tires last as long as possible.
Before pulling off the lot every day, daily pre-trip inspections should be made to ensure tires are inflated correctly.
“Proper inflation is critical for optimal treadwear and casing durability,” Davis says. “By rule, tire pressures should be checked cold before the truck starts running its route. Tires that measure below the recommended operating pressure should be properly inflated; any tire that is less than 80 percent of the specified pressure should be removed and replaced. Dual tires should be adjusted so pressure variations are less than 5 PSI [pounds per square inch] to ensure long, even wear and optimal casing durability.”
Davis says many fleet operators choose to place stickers on the fender above each axle to help drivers understand the pressure at which the tires should be operating. In-ground sensors also exist to provide more accurate measurements on tire pressure, axle load and total weight.
In addition to daily checks, managers should also schedule regular preventative maintenance every four to six weeks to address the rapid wear waste tires experience out on the road. This should include checks of tire pressure, tread depth, and tire and wheel conditions.
Tires should also be checked to ensure valve caps are on to prevent air leaks and protect from dirt and moisture.
“Dual tires should be matched within a 4/32-inch tread depth and within 5 PSI to prevent fast and irregular wear. If irregular wear patterns are noted, axles should be checked for alignment,” Davis says.
Because tires in waste applications wear quickly, they may not need regular rotation. However, if irregular wear patterns develop, a rotation may assist in prolonging the life of the unit.
“As a general rule, the right steer tire will wear faster than the left steer tire,” Davis says. “To maximize steer tire life, a rotation at 50 percent of the tire’s life may be necessary to extend its use, especially if the right front is wearing faster than the left front. Likewise, the rear axle on dual drives will wear faster than the front axle.”
Fleet managers can rotate tires across axles when the rear axle has 4/32-inch less than the front axle. Doing so wears both axles evenly and simultaneously. Davis also recommends rotating drives in an ‘X’ pattern and reversing the rotation of the tires.
In addition to tracking the physical condition of the tires, fleet managers should also regularly track several pieces of data for more efficient, cost-effective operations.
Tracking the cost per hour to removal can give fleet managers a clear picture of the issues affecting tire wear and performance. Davis says managers should ideally maintain records on as many tires as possible, but even tracking a subset in the fleet can give insight into which tires are operating at the lowest cost.
Keeping track of scrap and non-retreadable tires can also be beneficial, as tire dealers can review this inventory to determine if the tires are coming out of service early and, if they are, what the potential underlying cause may be.
Aggregating data from previous preventative maintenance checks can also be useful to determine how well the tires are being maintained. “If these routine checks uncover a number of incidences of irregular wear, underinflation or other tire conditions, additional maintenance is needed to optimize the tires’ performance,” Davis says.
Davis says it’s also useful to track downtime frequency and causes. “Tracking the issues that remove trucks from service, whether they include frequent punctures or driver error, can help fleets find solutions to stay up and running and reduce cost,” Davis says.
Retread or replace?
No matter how well managers conduct maintenance checks, tires are subject to wear sooner or later.
Retreading tires is an option for fleet managers to extend the life of their tires significantly, Davis says. Doing so requires the tire casings to be in workable condition, which is typical when proper fleet management programs are in place.
“Retreading is an integral part of a good tire maintenance program and can be a great, safe way to drive down the cost of a fleet’s tire program. It is not uncommon for waste haul fleets to retread the same casing three to four times or more, though the suitability for retreading may vary based on each fleet’s unique operating conditions,” Davis says. “Retreading provides fleets with significant savings—as much as 40-60 percent of the cost of new tires.”
Davis says retreading tires is the only tire maintenance service that cannot be performed in-house.
Typically, worn tires are sent to a retread facility, where technicians inspect casings to determine whether the tire should be retreaded or scrapped.
Davis says the usual turnaround time for a retread is about one week. However, turnaround times may vary by retread plant and according to the fleet’s needs.
Retreading can only be done so many times until the tire needs to be replaced entirely.
“DOT [department of transportation] regulations state that a tire must be removed when it has worn down to 4/32-inch tread depth on the steer [position] and 2/32-inch tread depth on drive or trailer positions,” Davis says. “In addition to measuring tread depth, fleet managers should regularly review tire conditions to look for damage such as cuts, snags or other types of irreparable damage that may warrant replacement.”
Davis also says fleet managers should keep dual tires top of mind when replacing primary tires, as the duals should be matched so there is no more than a 4/32-inch variation in tread depth side by side or across the axle.
The life of a tire can be affected by factors ranging from truck configuration and driving style to road hazards and tire position. But with a proper maintenance program in check, managers can maximize service life and keep their haulers on the go.
This article originally appeared in the September issue of Waste Today. The author is the assistant editor of Waste Today and can be reached at email@example.com.