WB6309B Ultimate Heavy-Duty Deep Groove Ball Bearing – SINOTRUK Homan OEM for Versatile Rotary Applications

Versatile deep groove ball bearing for high-speed and moderate load applications – The OEM WB6309B Deep Groove Ball Bearing is engineered to provide reliable, low‑friction rotary support in gearboxes, driveline flanges, and auxiliary drives. Manufactured from premium bearing steel to ISO 492 class P6 standards, this bearing offers exceptional radial and axial load capacity with minimal noise. For guaranteed compatibility and performance, always choose genuine Sinotruk Homan parts.

The WB6309B bearing is dimensioned as 45 mm inner diameter, 100 mm outer diameter, and 25 mm width – a standard 6309 size but with enhanced internal clearance (C3) and a superior cage design for heavy‑duty truck environments. It is suitable for applications such as transmission input shafts, wheel hubs (non‑drive ends), and power take‑off units requiring quiet, high‑speed operation.

English: Deep Groove Ball Bearing WB6309B

Russian: Радиальный шарикоподшипник WB6309B

Spanish: Rodamiento de bolas de ranura profunda WB6309B

Why the WB6309B Deep Groove Ball Bearing Sets the Standard for Versatile Rotation

The WB6309B is a single‑row deep groove ball bearing with a C3 radial internal clearance (greater than normal), making it particularly suitable for applications with moderate to high speeds, shaft expansion, or misalignment. Its deep uninterrupted raceway grooves allow the bearing to accommodate both radial and axial loads in either direction, offering a compact, economical solution for many heavy‑truck components.

The bearing rings and balls are manufactured from vacuum‑degassed 100Cr6 (AISI 52100) steel, hardened to 60‑64 HRC for excellent wear resistance and fatigue life. The raceways are superfinished to a mirror‑like surface (Ra ≤ 0.1 μm), reducing friction and noise. A pressed steel cage (or optional polyamide) maintains even ball spacing and low running torque.

Compared to standard 6309 bearings, the WB6309B features a higher precision grade (ISO P6) and is subjected to 100% noise testing (SQF level V2). The result is a bearing that runs quietly, even at speeds up to 6000 rpm (grease) or 8000 rpm (oil), and delivers a fatigue life (L10) exceeding 10,000 hours at rated loads. This makes it the preferred choice for SINOTRUK Homan truck gearboxes, auxiliary drives, and idler pulleys.

Complete Technical Specifications – SINOTRUK Homan WB6309B Deep Groove Ball Bearing

Engineering Excellence of the WB6309B Deep Groove Ball Bearing

The WB6309B bearing is produced on fully automated CNC grinding lines that ensure sub‑micron accuracy. The rings are ground using multi‑step cycles, then honed to a superfine finish. The balls are sorted into grade 10 (0.01 mm diameter variation) or better, guaranteeing smooth rolling and reduced vibration. The pressed steel cage is formed from deep‑draw sheet and then heat‑set for dimensional stability.

The C3 internal clearance is specified to accommodate shaft expansion when operating at high temperatures (e.g., near the engine or exhaust). This clearance class also reduces friction torque at high speeds, prolonging lubricant life. The bearing is pre‑greased with a high‑quality lithium‑based EP grease that provides long‑term lubrication for up to 50,000 km or two years in typical truck applications.

Each bearing is 100% noise‑tested (SQF) on a vibration test rig, ensuring it falls within V2 (very quiet) limits. Random samples are tested for dynamic capacity according to ISO 281, for static capacity, and for debris tolerance. The result is a bearing that meets the demanding requirements of SINOTRUK Homan powertrain systems, where reliability and low noise are paramount.

Superior Material & Wear Resistance

The 100Cr6 steel is vacuum‑degassed to eliminate harmful non‑metallic inclusions, dramatically increasing fatigue life. After hardening, the rings are tempered to relieve stress while retaining high hardness. The raceway surfaces are superfinished (Ra ≤ 0.1 μm), reducing friction and allowing the bearing to operate cooler at high speeds.

The lithium EP grease used is temperature‑stable and resistant to water washout. For applications requiring oil lubrication, the bearing is supplied clean and lubricated with a light preservative oil; the customer may then flush and apply the desired oil.

Easy Installation & Compatibility

The WB6309B is a standard 6309 size and will directly replace any 6309 bearing in SINOTRUK Homan equipment. The bearing can be installed by pressing the outer ring into the housing (tight fit) or by pressing the inner ring onto the shaft (tight fit). Always apply force to the ring that is being press‑fitted; never press through the balls. Use an installation sleeve that contacts the entire ring face.

The recommended shaft tolerance for a standard fit is ISO h6 (45 mm shaft: 44.991‑45.000 mm). The housing bore tolerance is ISO P6 for a tight fit (100H7 for a clearance fit). When replacing a bearing, always replace the shaft seal and check for housing wear.

Installation Guide for the Deep Groove Ball Bearing

1) Inspect the shaft and housing for scratches or burrs; clean thoroughly. 2) Check the bearing for handling damage, then remove the protective oil film. 3) Apply a thin layer of high‑quality grease to the bearing bore and outer diameter (if press‑fitting).

4) For a press‑fit on the shaft, use a press sleeve that contacts the inner ring face. Press the bearing onto the shaft until it seats against the shoulder. 5) For a press‑fit in the housing, use a sleeve that contacts the outer ring face only. 6) After installation, ensure the bearing rotates freely with no binding.

7) If the bearing is being used in a gearbox, fill the housing with the specified quantity of oil before final assembly. 8) If grease‑lubricated, pack the free space in the housing 30‑50% full; avoid over‑greasing, which can cause overheating. 9) Install the shaft seal and test the assembly.

Maintenance & Troubleshooting Tips

The WB6309B bearing generally requires no maintenance beyond periodic relubrication if the application is grease‑fed. A small amount of grease can be added through a fitting if present; excessive grease causes overheating. Symptoms of bearing wear: increased noise (rumble, whine), vibration, or excessive shaft end‑play.

If the bearing fails, examine the raceways for spalling, the balls for flat spots, and the cage for damage. Common causes: contamination, improper mounting (dinged raceways), or loss of lubrication. Always replace the bearing and the shaft/housing if worn. Do not reuse a bearing after it has been removed – the clearance may have been upset.

For high‑speed applications (above 5000 rpm), use oil lubrication rather than grease. The C3 clearance is essential to prevent thermal seizure under heavy load.

Quality Certifications & Rigorous Testing – WB6309B

The WB6309B bearing is produced under IATF 16949 and ISO 14001 certified systems. Each bearing is 100% inspected for bore/OD/width (CMM), radial runout, axial runout, and noise (SQF). Random samples are subjected to life endurance testing (L10 life verification at 55.9 kN dynamic load), debris tolerance (contaminated oil test), and corrosion testing (240h salt spray).

The bearing meets or exceeds ISO 15 (rolling bearing dimensions), ISO 492 (tolerances), and ISO 281 (life calculation). A laser‑etched batch number on the outer ring provides full traceability to raw material certificates. Counterfeit bearings often have poor surface finish, incorrect grade balls, or missing etches. Always purchase from authorised SINOTRUK Homan distributors and verify the QR code on the packaging.

Real-World Field Performance Data

A fleet of 600 SINOTRUK T7H tractors in Germany replaced gearbox idler bearings with the WB6309B. Over 24 months, gearbox noise complaints dropped by 85% and no bearing‑related failures occurred. The low‑noise characteristic of the genuine bearing was credited for improved driver comfort.

Another user – a mining contractor in Indonesia – installed these bearings in PTO drive shafts on 350 HOWO dump trucks. After 2 years and over 10,000 operating hours, bearing replacement rates were 90% lower than with generic bearings. The C3 clearance prevented seizure when the shafts reached high operating temperatures.

Packaging, Anti-Counterfeit & Genuine Identification

Each genuine WB6309B bearing is packed in a sealed anti‑rust sleeve inside a SINOTRUK Homan branded carton. The box includes a QR code and a hologram label. The bearing itself has the OEM number laser‑etched on the outer ring and is pre‑lubricated with a thin rust‑preventive oil.

Counterfeit bearings often have a rough outer surface, missing etch, or an unsealed box. The genuine bearing rotates smoothly with no detectable roughness and has a uniform silver appearance. Always scan the QR code before installation. Using a fake bearing can lead to premature failure, gearbox damage, and vehicle downtime, voiding the warranty.

Summary: The SINOTRUK Homan Deep Groove Ball Bearing (OEM WB6309B) delivers high load capacity, low noise, and reliable high‑speed operation for gearboxes, PTOs, and auxiliary drives. Ensure smooth and quiet rotation – choose this genuine component trusted by fleets and mechanics worldwide.