CSA and Tire Basics
Poor repairs are a significant source of citations, says Doug Jones, Michelin Americas’ customer engineering support manager. He also notes the big fleets with their own shops tend to jettison a tire that can’t be fixed easily. But small operators sometimes find a shop that will repair a tire that’s too severely damaged or fail to perform a difficult repair properly.
• Give the tread a careful check with a tread depth gauge. Jones says that irregular wear of a tire that has good tread in most areas may still cause it to flunk the tread depth test. A spot that’s worn below 4⁄32-inch on a steer tire in two adjacent tread section, or below 2⁄32-inch on a drive or trailer tire, can get you a citation.
• Make sure the tire is not rubbing on the vehicle or in contact with a dual tire next to it because of improper mounting.
• If the truck is loaded near its weight limit, make sure the tires are of the proper weight ratings for the gross combination weight. Tires carrying more than rated weight can overheat and fail, so this will get you a citation. Mooney says this problem is less likely to attract attention in a standard roadside inspection than at a weigh station.
• Remove any objects trapped between tread sections, Miller says. Such objects often lead to serious damage to the tread. Jones says to look down into the grooves for significant cracks or the appearance of cords, symptoms indicating the tire needs to be replaced. Use a flashlight for better visibility.
• Check for chunking or tearing of the tread, Decker says. Run your hand across the tread carefully. Do you feel sharp edges? It’s a sign of irregular wear. Check further to ensure tread depth is adequate across the tire.
Good vehicle maintenance
For maintenance beyond the pretrip, certain procedures can help head off problems, especially related to irregular wear and uneven tread depth, that could result in a citation.
“Regular alignment will cover the majority of tire issues,” Decker says. “When it comes to items such as bearing maintenance and damper maintenance, that’s where you see the best fleets really separating themselves from the pack. It’s so tempting to save costs in the short term by skimping on regularly scheduled preventive maintenance.”
Don’t wait for tire trouble to signal the need for work on the chassis. Do it regularly so your tires will last longer.
Regular alignment means not only setting the toe-in and checking caster and camber on the front axle, it means total vehicle alignment. The latter refers to lining up the drive axles with the centerline of the tractor, and lining up the trailer axles with the kingpin. Misalignment leads quickly to irregular wear, along with wasting fuel.
Wheel bearing maintenance is critical because loose bearings lead to irregular wear of the tread and worn spots that can also leave you shy on tread depth, even on newer tires. Proper, even mounting on the rim, as well as wheel balance, and shock absorber (damper) maintenance, Decker says, will also help eliminate irregular wear and low tread depth areas by preventing the tire from hopping down the road.
“Specifying the correct tire for a given application will also help to avoid problems,” he notes.
“Getting drivers to perform a good pre-trip is only the first step,” Walenga says. “If he finds a problem, you need to repair the tire before the truck moves. Having spare tires already mounted for quick change can help get the truck on the road fast and avoid the temptation to send it out with a damaged tire.”