By David A. Kolman, Editor, Fleet Maintenance Magazine
A newly published technical paper, Preload and Drag Effects Due to Torque Applied to Spindle Nuts on Tractor-Trailer Wheel End Systems, discusses the relationship of tapered roller bearing adjustment with respect to values of bearing preload force and rotational resistance caused by varying amounts of spindle nut installation torque.
The findings come from research done by George Allan Hagelthorn, P.E., of Rather Engineering, P.C. - a company that provides engineering consulting services for the commercial highway transportation industry.
“The intent of the study was to promote the incentive to develop improved recommended practices for tapered roller bearing preload adjustment,” says Hagelthorn. “General acceptance of a controlled preload adjustment concept - a method for preloading threaded fasteners by use of a torque wrench - has not been realized.
Rather Engineering’s research demonstrates that there are a number of techniques for controlled preload that can result in improved performance, greater reliability, some fuel savings and an added measure of safety to prevent wheel separations.
Hagelthorn intends to present the technical paper to the 2013 Annual Technology & Maintenance Council (TMC) Meeting & Transportation Technology Exhibition, set for March 11 to 14 at the Gaylord Opryland Hotel & Conference Center in Nashville, TN.
TMC is North America’s premier technical society for truck equipment technology and maintenance.
Hagelthorn says he hopes his technical paper will help lead to a TMC Recommended Maintenance Practice (RP) for more effective wheel bearing adjustment procedures.
TMC’s RPs are a collection of best practices that assist equipment users, vehicle/component manufacturers and other industry suppliers in the maintenance of commercial vehicle equipment.
The technical paper, Preload and Drag Effects Due to Torque Applied to Spindle Nuts on Tractor-Trailer Wheel End Systems, can be found in Fleet Maintenance’s online Media Center at www.vehicleservicepros.com/media-center.