Take Con-way, for example. A couple of years ago, the company embarked on a program to reduce its number of road calls. "Tires account for about half of in-route breakdowns," says Bill Fowler, director of maintenance. "We said, that presents a huge opportunity to prevent road calls. So we became much more aggressive at managing our tires. [As a result] we literally had over 100 percent improvement in our road calls."
Pay attention to your tire program, and like Con-way, you may be able to drastically cut down on unscheduled downtime.
A good tire program also can cut scheduled downtime. If you keep tires well maintained, the result is less wear and proper wear, so they have to be repaired or replaced less frequently. Added dividends include better fuel mileage and tires that can be retreaded for more savings.
After talking with tire makers and fleets, we've identified seven keys to maintaining uptime for truck and trailer tires.
1. KEEP TIRES PROPERLY INFLATED
Keeping tires properly inflated is the number one thing you can do for maximum uptime. Low tire pressure can lead to uneven and premature tire wear, failure on the road, and earlier replacement, as well as damage to the casing, making it useless when it comes to retreading.
Yet many fleets don't check air pressure often enough or properly.
"The proper inflation, and the inflation of a set of dual tires within 5 psi of each other, takes care of the lion's share of tire problems," says Curtis Decker, national manager, field engineering, for Continental Tire North America.
This means doing away with a tire billy and getting a good tire pressure gauge – either a new gauge, or an existing one that has been properly calibrated and hasn't been dropped on the ground.
In addition, a growing number of fleets are discovering that tire pressure monitoring systems or central tire inflation systems are well worth the investment.
A tire pressure monitoring system automatically monitors the pressure on truck and trailer tires, letting the driver know air is needed. Central tire inflation systems also monitor tire pressure, but they also automatically add air when pressure drops below a certain level.
Each has its pros and cons.
"One of the problems that I have with tire pressure monitor systems is that it depends on the interaction of someone after the alarm has sounded," Decker says. "The active inflation systems keep the air going to the tires at the same time that the operator is made aware of the issue." He adds that an inflation system can better keep the wear pattern of the tire smooth.
Over-reliance on technology, however, can backfire, says Guy Walenga, engineering manager for commercial products at Bridgestone Firestone North America. "Technology can help maintain tire pressure, but nothing can replace a thorough visual inspection of your tires," he says. Without a driver or technician regularly checking tire pressure manually, such inspections can be overlooked, possibly allowing tread depth to get too low or missing signs of tire damage. "Penetrations, cuts, rock chipping, brake locks, curb damage, and other injuries still need to be noted and addressed."
2. PERFORM REGULAR MAINTENANCE AND INSPECTIONS
As Walenga notes, there's more to a good tire maintenance program than inflation. How often should maintenance be performed? Any time you are doing any other kind of maintenance on the equipment is a perfect opportunity to check the tires, but it should be more frequent than that. Just how frequent is the big question.
"I do not subscribe to someone riding the yard every day and checking air pressures. I'm not sure it's cost justifiable," says Darry Stuart, president of the fleet consulting firm DWS Fleet Services.
Check them weekly, recommends Ron Gilbert, director of sales, commercial products at Toyo Tire USA. "This includes a visual inspection for nails, irregular wear and any other foreign objects in the tire."
Inspections also should include measuring the tread depth and noting a tire's physical condition. Keeping records on tread depths can help you determine your tire cost per 1/32, while making notes of a visual inspection can help pinpoint the causes of tire problems and also offer clues toward other equipment problems.
"Quite often tires are removed while there is still usable tread depth left on the casing [because there's] an irregular wear pattern," says Continental's Decker. "People are quick to believe that irregular wear patterns on a tire are caused by the tire itself. Yet every component of the wheel end position can have an effect on the wear pattern of the tire."
This means getting ahead of potential problems. This can be done by setting up a preventive maintenance program with the help of the Technology and Maintenance Council's Recommended Maintenance Practices manual. Regular PMs are the key to catching a problem before it develops into irregular wear or unscheduled downtime. For instance, if a fleet waits until a shock absorber is leaking oil, allowing the wheel end to bounce repetitively, you can expect the tire to be damaged in the process. The same goes for not keeping tires properly aligned.
3. CHANGE AND ROTATE TIRES
When you change one tire, you need to change others, too.
"If one steer tire need to be changed – for whatever reason – change the other one as well," says Timothy Miller, marketing communications manager of corporate tires at Goodyear. "For drive tires, replace tires by axle. If one tire needs to be changed, replace all the tires on that axle so that all tires match in brand, type, age and tread depth."
This same logic applies when it comes to rotating tires, which should be performed during regular PMs to help get even tire wear. "Left steer tires tend to wear a little faster than right steer tires," Miller says. "If the steer tires are in the 25 percent to 75 percent wear range, it might be best to flip them left to right and right to left just to increase the chances they will both require replacement at the same time."
The same is true for tires on tandem axles. The drive tires on the rear tandem will tend to wear a little faster than the tires on the forward axle. During PMs is a great time to pull all of the tires off and switch them from axle to axle, even reversing the direction of travel to get even wear patterns, while also allowing a technician the opportunity to inspect them more closely than he can when they are on the truck or trailer.
Any time you change out a tire on a wheel, you need to follow standard industry procedures. Something as simple as having the right bead lube is essential to making sure tires mount correctly.
When you take that old tire off, don't just throw it on the scrap pile and forget about it. That old tire just may be the Rosetta Stone when it comes to giving indications of other problems.
"Scrap tire analysis is an excellent way for fleets to understand why tires are failing or have to be removed from service," says Doug Jones, customer engineering support manager for Michelin North America. "By evaluating each tire when it is removed from service, fleets can determine recurring problems or wear patterns that can be fixed, minimizing overall downtime."
4. CHOOSE THE RIGHT TIRES
When it comes to truck tires, like many things these days, there are a lot of choices. It's no longer just a case of picking steer, drive and trailer tires. Tires have gotten more application-specific for each wheel position so they will last longer and give better performance. This also means you have to really be up to speed in choosing the right one for your operation.
Tire makers can offer a lot of guidance when it comes to finding the right kind of tires. A good local dealer can make things even easier.
Goodyear's Miller says this means ultimately selecting tires that deliver the most miles to removal. Admittedly, he says, this is easier said than done. Good record-keeping is the key. "Since tire companies are always coming up with improvements in wear and durability, you must make sure you are running tests to see if something better is being offered," he says. "This may mean that the tires in each wheel position might be different brands."
For some fleets, the best tires are single-wide tires, where one extra-wide tire replaces a dual set. The main benefit is weight savings, allowing fleets to haul more cargo, but the tires are more fuel efficient, and, most important for uptime, they last longer.
Joplin, Mo.-based CFI tested single-wide tires extensively before converting its entire tractor fleet as trucks were traded. "We found that our failure rate of tires actually went down with wide-base," says Bruce Stockton, vice president of maintenance at the 2,500-truck fleet. "We attribute that to the driver being able to tell or see visually when they have a low tire, as opposed to having duals where one tire is next to the other and is essentially holding it up."
Stockton says availability of these tires in case of a roadside emergency is no longer an issue, noting there are very few places that don't have the tires available. They have even been running the tires on some trailers that go to Mexico, though he says if there is a problem there, the tire is typically replaced with two duals temporarily.
Another fleet that's going full steam ahead with single-wide tires is Arkansas-based flatbed hauler Maverick Transportation. They are running them on all of their tractors and testing them on trailers. Maverick records show that getting a single-wide tire replaced during a roadside emergency versus a low-profile 22.5 tire does take slightly longer. Part of the reason may be that when these tires do fail, there is often a rim failure as well, because the rim hits the ground.
That's one reason Maverick is installing 1,200 Meritor/Wabco Integrated Vehicle Tire Pressure Monitoring systems on its tractors. "Our goal with that is to have that information feed back to our road assist department in-house to monitor those readings," says Brent Hilton, director of maintenance. "Whenever we have a failure or a low pressure alarm ... we contact the driver and have them go to a repair facility."
5. DON'T FORGET THE VALVE STEMS
You can spend a lot of time choosing just the right tire and making sure you have a good preventive maintenance program and still miss a potential downtime culprit: valve stems.
Two items that are typically under-inspected are the condition of the wheel valve stem grommet and the valve core, says Henry Box, a technical services director for Toyo Tire USA. "Periodic inspections that can confirm the grommet is not aged and is properly tightened, and the valve core is free of debris and protected by the use of a valve cap, will go a long way to help minimize downtime."
That's exactly what Con-way discovered. "We were seeing tires losing air pressure, so we would pull them off and hold them and analyze them over several days, and that's where we identified a valve stem problem," says Bill Fowler, director of maintenance.
Walenga recommends using steel or carbon fiber (dense plastic) valve caps with an inner rubber seal. These are designed to provide the final seal for the tire/wheel assembly, but he also notes that taking the valve caps on and off hurts efficiency in checking air pressure. "Try the flow-through valve caps and stems like the Alligator V2B, a double seal check valve that does not require another cap." For added insurance, he says, replace the valve stem, grommet and valve core any time you replace a tire.
6. MANAGE TIRE EMERGENCIES
No matter how good a job you do when it comes to selecting and maintaining tires for your truck and trailer, roadside emergencies can and will happen. The key, says John Cooney, director of sales with Yokohama Tire, is to "be prepared for the inevitable." This means having an emergency service provider lined up in advance that can get your truck up and running, even if it's at 3 a.m. and sitting along a deserted road in Slapout, Ala. This also means knowing who your driver should call, whether it's your maintenance department, dispatch or roadside emergency provider.
Most tire makers have roadside emergency service you can sign up for, and there are also independent companies that can provide the same service, as well as address other roadside truck breakdown problems. The key is to finding one that provides the right level of service for your operation at a price you can afford.
7. RETREAD RIGHT
Retread tires can improve your uptime because they fail less than new tires. You may find that hard to believe, especially if you remember using retread tires some 15 years ago or more, but it's true, according to the Tire Retread Information Bureau.
The reason? The extensive screening that tire casings are put through before they are retreaded, thus weeding out the ones that otherwise could fail on the road.
The key to getting your tires retreaded is taking care of them from the start. Tires to be retreaded should be removed from service well before the legal limit of 4/32 for steer and drive tires and 2/32 for trailer tires. "In addition to having degraded traction properties, tires with less than 6/32 or tread are much more likely to be seriously damaged by nails and other road hazards," says Eugene Johnston, business development manager for tire retreader Bridgestone Bandag.
Johnston also recommends purchasing new tires that come with a retreadability warranty. "The fact that the manufacturer is willing to stand behind their product over its full life cycle is a good indication that the casing has been engineered to perform above the bare minimum requirements."
Getting the most uptime from your truck and trailer tires is relatively painless. One representative from a tire maker likens it to taking care of yourself, such as eating right and exercising: It sounds simple, but how many of us really follow such a program? As a precaution, and if we are fortunate, we have health insurance, because sooner or later we break down for one reason or another and need help to get back in the game. Truck tires are no different. Give them a little care and attention and they will take care of you – but always be prepared for the inevitable.