Issue link: http://read.dmtmag.com/i/34501
Note: The bead seating surface of the tire and wheel do not match up as shown in previous illustration. This incorrect seating is the result of mismount. The TMC (Technology & Maintenance Council) specification is 2⁄ 32nds (0.062 inch). If both wheel and tire are lubricated and initial air inflation is done with the tire flat, then 1⁄32nd inch or less variance around the tire should be obtainable. Check for this mismount condition with the 6 inch ruler, measuring in 4 locations around an unladen assembly. Check for hub to wheel clearance on hub piloted assemblies with the feeler gauge. If the measured high spot lines up with the feeler gauge gap, rotate the assembly so the gap is at the top, loosen the lug nuts, and allow gravity to center the wheel on the hub. Hand tighten the top nut, tighten all nuts in the proper sequence, recheck for runout, and retorque. Verification of radial (top photo) and lateral (bottom photo) wheel runout is another step to be considered. TMC tolerances are 0.070 inch on tubeless steel disc wheels and 0.030 inch on tubeless aluminum disc wheels. PROCEDURE TO CHECK THE WHEEL FOR RADIAL AND LATERAL RUNOUT • Mark two studs and the wheel with a crayon. • Remove the tire/wheel assembly from the hub. • Mark the tire and wheel at the valve stem. • Dismount the tire from the wheel using proper procedures. • Clean the wheel flange area with a wire brush. Check the wheel for any damage. • Identify and mark the wheel to indicate where the radial and lateral high and low spots were found on the tire. On cast spoke and demountable rim assemblies, loosen and properly retighten the rim clamp nuts to the proper torque. Recheck for runout. • Place the wheel back on the marked hub with the wheel matched to the marked studs. Use 3 lug nuts and properly torque. • Measure radial and lateral runout on the inside and outside flange. • See if the readings match up to the tire. • Readings greater than 0.030" for aluminum wheels and 0.070" on steel wheels indicate high runout. Section Nine: Appendix 135