The Commercial Vehicle Safety Alliance (CVSA) has announced this year’s International Roadcheck inspection blitz will be held May 17-19 with a focus on wheel ends.
The wheel end is the heart of the axle and its margin for error in setting end play – how loosely or tightly the bearings sit inside the hub – is thinner than a sheet of paper.
CVSA claims violations involving wheel end components historically account for about 25% of the vehicle out-of-service violations discovered during International Roadcheck, and past Roadcheck data routinely identified wheel end components, excluding brakes, as a Top 10 vehicle violation.
The Technology & Maintenance Council Recommended Practice 618B suggests .001 to .005 inches of end play, with a goal of trying to get as close to either number as possible. A sheet of paper is roughly .004 inch.
Among the benefits of manually adjusting wheel bearings is the confidence of knowing the wheel end is within the TMC recommended specification, “assuming the technician concludes the installation with a dial indication to confirm end play,” said Stemco Wheel End Product Manager Vincent Purvis.
Properly checking end play requires removing the hub cap or axle, which TravelCenters of America Director of Technical Service Homer Hogg said might not always make the most sense every time you raise the wheel end, “but you can certainly spin the assembly and check for roughness,” he added. “You can also try to push in on the top of the wheel to see if there is any movement.”
An experienced technician, Hogg said, should know how to tap the assembly in the right locations and to hear and feel a loose wheel bearing, “but remember that the best way to check it is with a dial indicator.”
