On Again, Off Again

Five tips for keeping your wheels on the go:

1. Lubrication: The hub pilots should have a generous coating of non-water-based lubricant (don’t, however, lube the face of the wheel, the hub, or the brake drum). In a “dry pilot” condition, corrosion can build up between the wheel and hub bore. The corroded surfaces will make wheel removal difficult. If this is the case, use a penetrating oil to loosen the nut. Don’t use heat.

2. Mounting: Position one of the hub’s pilot pads at the 12-o’clock position, then firmly place each wheel (assuming a dual assembly) on the pads. Keep the handholes aligned for easy access to the tire valves and hand-tighten all the flange nuts.

Next, mechanically tighten the nuts to the recommended torque. Use the sequence designated by the OEM (usually a crisscross pattern, starting at 12 o’clock, so the pressure of each tightened nut helps seat the wheel straight and even against the hub).

3. Torque: The recommended torque for 33-mm M22x1.5 two-piece flange nuts is 475 pound-feet, plus or minus 25 pound-feet. Flange nuts with a 1-1/2-inch hex head design, among other designs, will have different torque requirements. Check with the manufacturer to ensure you know the proper torque value.

If you use an air wrench, keep it adjusted to ensure application of the right amount of torque and routinely double-check a tightened cap-nut with a torque wrench. It’s recommended that you check the torque of a newly mounted wheel after 50 to 100 miles of operation and at least every 10,000 miles of running thereafter.

4. Visual inspections: At tire changes, inspect the nuts and studs for cracks and damaged threads. Stud-hole cracks on the hub/drum side of the wheel can be caused by the support surface not being flat or of sufficient diameter. Check the hubs and drums to ensure they’re flat to at least 13-3/16 inches, although 13-1/2-inches is better still.

5. The right info: Make sure your maintenance shop has up-to-date service manuals, since these documents provide more detailed application and service information.