A new installation procedure developed by Rather Engineering using the CPAN axle nut system will reduce operational expense caused by excessive tightening of axle nuts.

Maintenance technicians can adjust tapered roller bearings with either controlled preload or endplay. Following this three-step procedure, the wheel-end assembly will be completed by installing the hub cap:

  • An experienced maintenance technician can install tapered roller bearing wheel-end assemblies without excessive drag (resistance to rotation). Acceptable tightness, either controlled preload or endplay of the adjustment nut, can be installed and verified before proceeding.

  • After the maintenance technician has assurance the bearing adjustment is acceptable, the outer retainer nut and tabbed washer are positioned against the adjustment nut with light torque. The tab of the washer bends to engage the retainer nut, preventing further movement.

  • Installation of the CPAN nut system is completed by applying reverse torque to the inner adjustment nut to jam it outward against the retainer nut. This back-off procedure does not change the lateral position of the adjustment nut on the axle, and the amount of preload or endplay originally applied will be “locked in.”

Details about these installation instructions are available on www.CPANnut.com.
Circle #210 on Reader Service Card