Trailer Wheel Hub Bearing Set

Function

The tapered roller geometry of this bearing set allows each hub to carry simultaneous radial loads — the dead weight of the plant acting vertically through the axle — and axial thrust loads generated during cornering, cambered road surfaces, and lateral ground slopes encountered during site access. Correct bearing function maintains hub concentricity, prevents heat build-up in the hub cavity, and keeps the wheel-end seal undistorted, thereby protecting the axle shaft and brake hardware housed inboard. A deteriorating bearing set produces progressive hub vibration that accelerates tyre wear, transmits cyclic stress into the trailer drawbar and fifth-wheel coupling, and — left unchecked — leads to wheel-end seizure during a road move between projects. Replacement at the intervals specified in the AVL-MAP maintenance schedule preserves road-permit compliance, protects connected components, and eliminates the risk of unplanned stoppages in transit.

Construction & quality

Both inner and outer bearings are manufactured from GCr15 chrome-alloy steel (equivalent to 100Cr6 / 52100), with raceway surfaces ground and superfinished to Ra ≤ 0.4 µm and through-hardened to 60–65 HRC. Tapered rollers are precision-profiled with crowned ends to reduce edge-stress concentration under lateral loading. Cages are pressed steel, phosphated for corrosion resistance and compatibility with lithium-complex grease. The two bearings in each set are dimensionally matched at manufacture to achieve the Avelta-specified endplay window (0.05–0.15 mm) without selective shimming at first installation. The double-lip nitrile (NBR) grease seal retains lubricant within the hub cavity and excludes road dust, water, and grit. All components are supplied as a single complete kit together with the bearing nut, locking washer, and fitment instruction sheet, so no additional consumables need to be sourced separately on site.

When to replace

• Audible rumbling or growling from the wheel hub, most pronounced at 50–80 km/h on a smooth road surface
• Hub temperature exceeding 70 °C above ambient after a short road run, confirmed with an infrared thermometer at the hub cap
• Visible lateral play when the wheel is rocked at the 3 o'clock and 9 o'clock positions with the hub raised clear of the ground — indicating loss of bearing preload
• Grease found during a scheduled hub inspection that is darkened, gritty, or carries visible metallic particles — indicating race or roller surface breakdown
• Spalling pits, fretting marks, or roller-path discolouration visible on the races during a full hub strip-down inspection