Vehicle & Equipment · Driver Training VideoWheel-Ends — Lug Nuts, Wheel Seals & Hubs

Wheel-ends fail slow, then fail all at once. A wheel that comes off a moving truck almost always started as a warning sign somebody walked past during a pre-trip.

Start with the lug nuts

Federal rule 49 CFR 393.205 says no wheel or rim can be cracked or broken, no stud or bolt hole can be elongated, and no nut or bolt can be missing or loose.

If your rig runs loose-nut indicators — the small caps or flags that rotate out of position — check them every trip. They're cheap insurance, and they'll catch movement between inspections that your eye alone would miss.

Torque matters as much as presence. A nut that's threaded on but under-torqued still walks itself loose over miles of vibration.

Now the hub

Check the oil level through the sight glass on oil-bathed hubs, or the fill plug on greased units. Oil should sit between the fill lines — not low, and never milky or foamy.

Feel for heat and check for play. After a stop, a hub that's noticeably hotter than its neighbors on the same axle, or a wheel with any wobble when you rock it top and bottom, is telling you a bearing is failing right now.

A loose or missing lug nut, a leaking seal, or a hot hub isn't a "note it and drive" defect.

Your company standard: walk every wheel, every pre-trip — not a glance from across the yard. Check lug nuts for rust trails and gaps, check hub oil for level and color, feel for heat, and check for play.