Best Practices for Tire Maintenance | Semi Truck Repair
Many fleets standards and practices vary a little, but as a company that services trucks and tires, we thought we’d put out our own “best practices” here on our blog.
We’ll start with the ol’ standby – air pressure. It’s the easiest thing to control and one of the most common causes when it comes to tire failure. Proper air pressure reduces blowouts, increases tire life and improve fuel economy. In a perfect world air pressures would be adjusted each time the load changes, but we certainly don’t live in a perfect world. The real world and our time constraints are much different. Assuming all loads are legal, air pressure should be based on the load carried and axle rating, not by the maximum air pressure stamped on the side of the tire. Most fleets will hedge air pressure between 5-10 psi.
Air pressure maintenance is the next key component to best tire practices. A visual inspection should be a part of every pre and post trip. If a tire looks low, then a physical check is needed. Tires should always be checked cold and seasonal temperatures should be taken into consideration. In many areas, a tire at 100 psi in August could be 90-95 psi in October. However, if you are regularly (within the same season) seeing a 10 lb variance in pressure, it should be checked for cause.
Next, let’s’ discuss drive tire rotation. Tires on the rear drive tire axle normally wear much faster (30-40%) than the front drive axle. Tires should be rotated when the tread depth difference front to back axle is between 6/32nds and 8/32nds. The ideal time to do tire rotations is when doing PM’s. Vehicles experiencing high scrub should rotate closer to a 6/32nd variance. We consider “best practice” to cross rear drive axle tires (left rear to right front & right rear to left front) and fronts straight back. However another option is to move front drive tires straight back and back tires, straight forward.
Steer tires rarely wear out equally. Normally the right tire shoulder wears out quicker due to driving patterns. Normal rotation for steer tires is 30k to 40k miles. If your fleet is noticing rapid tire wear though, you should consider crossing your steers around 20k miles.
Finally, we should cover pull points. The CVSA mandates that steers must be pulled at 4/32nds and drive and trailer tires at 2/32nds. To get maximum use out of a tire, many fleets will pull a steer at 6/32nds and move it to a drive or trailer position to use the remaining 4/32nds there. Keep in mind though, time of year and minimum traction requirements may dictate a different pull point for your fleet.