How nut torquing and backoff are used to set （用于设置有多坚果罐子和退下）.pdf

How nut torquing and back-off are used to set wheel bearings How do we adjust wheel bearings to meet the correct end-play specifications? Following is a simple, five- step procedure: 1. Torque the adjusting nut to 200 lbf-ft to seat the bearing components. Always rotate or oscillate the wheel while torquing the adjusting nut to ensure that the rollers are fully seated against the cone large rib. 2. Back off the adjusting nut one full turn or until it’s loose. 3. This is where you actually establish end play. Torque the adjusting nut to 50 lbf-ft while rotating the wheel hub assembly. 4. Back off the inner (adjusting) nut the appropriate amount as indicated by the chart at right; e.g., 1/6 of a turn for a 12- threads-per-inch front steer axle. See chart at right for the exact back-off amount. WARNING: Failure to back off the inner nut as described may cause the bearing to run hot and be damaged. If this happens during operation, the wheel also may lock or come off, causing a risk of serious bodily harm. 5. On a single-nut system, install a cotter pin. On a double-nut system install a jam nut and torque it to the proper specification, which varies depending on the size of the nut. Generally, jam nuts less than 2-5/8 should be torqued to 200-300 lbf-ft; nuts 2-5/8 and over should be torqued to 250-400 lbf-ft. See chart for exact torque specification. The final step is to use a dial indicator to verify the end play or free movement of the tire and wheel assembly along the spindle axis. We will discuss dial indicators in Part 7 of this series on bearing adjustment. Adjusting Nut Back Off Jam Nut Torque Axle Type Threads Per Inch Final Back Off Nut Size Torque Specifications 12 1/6 Turn Instal