Trailer tire rotation should be the same as the drive tires. There is no restriction on crisscross rotation, including directional steer tires that have worn 50 percent or more of the original tread. In fact, it is most often beneficial to rotate the tires so that irregularly worn tires are moved to a position where they are turning in a direction opposite the original position.”
Bridgestone/Firestone’s Walenga agrees, saying his company prefers to see the X-pattern used among tandem axles “because you then have a different edge to the outside.” He adds, “When looking at certain types of shoulder wear, after you fix the problem, you may have to break duals apart, moving them in and out.” The shoulder on the outside should no longer show the wear.
Such rotation can also help eliminate heel and toe wear, according to a diagram supplied by Yokohama. Keating says, “Steers should be rotated side-to-side. Drives are best rotated in an X-pattern, in pairs, but where that is impossible or impractical, drive tires can be rotated in pairs, front axle to back axle.”
Walenga adds that some fleets “rotate totally,” which means drives can go back and forth to steers and vice-versa. In this case, you need to use rib tires on all positions. While extra traction may be needed at times, he points out that chains are actually easier on rib tires than on drives that have lugs for aggressive traction, making the use of chains together with rib drive tires a practical way to operate.
To extend mileage on steers, swap them “at about one-fourth of the expected total mileage,” says Goodyear’s Tim Miller, marketing communications manager. For drives, “moving the rearward axle tires to the forward axle and vice versa,” he says, “will even out the wear and help create a situation where all the drive tires are more likely to need replacement at the same time.” As with the steer axle, rotating the tires to the other side of the vehicle “reverses the direction of rotation and helps clean up any irregular wear that may have started.” n
What to look for during rotation
If you uncover irregular wear during rotation, you need to correct the misalignment of steering or front axle wear parts, or of drive or trailer axles, that are causing the problem. Here are a few signs to look for while the tires are off:
• Michelin’s Doug Jones recommends inspecting wheel-end components for wear. Also, “Adjacent dual tires should not differ more than 1/4-inch in diameter (4/32-inch in tread wear). If there is a difference in tread wear, fit the least worn tire in the outside position. Curbing on dual applications often damages tire sidewalls. If so, rotate the wheel and tire to the inner wheel position.”
• Bridgestone/Firestone’s Guy Walenga says to take advantage of the chance to examine the sidewalls of inside duals. “Also, feel the tread to check for irregular wear,” he says. “And check to see if the tire is mounted concentrically. There should be a constant distance between the flange on the wheel and the guide ring on the tire.”
How often should you rotate?
No rotation schedule is so rigid that it’s worth purposely scheduling, says Bridgestone’s Guy Walenga. “We recommend doing it when the wheels are up anyway, and the truck is in for other service,” he says. Here are five takes on rotation frequency:
• At least once during the life of the tread. (Bridgestone’s Guy Walenga)
• At the halfway point of wear-out. (Yokohama’s Pat Keating)
• Only when irregular wear appears. (Michelin’s Doug Jones)
• Once at one-fourth of the total expected mileage, and possibly again at half to three-quarters total mileage. (Goodyear’s Tim Miller)