CAT 1J-6239 BEARING A

CAT 1J-6239 is a Caterpillar genuine tapered roller bearing assembly, an integrated heavy-duty bearing unit commonly used in rotating power transmission components such as gearboxes, drive axles, and differentials. It is suitable for heavy-duty, impact, and vibration conditions in medium to large-scale construction machinery, and features high load capacity, fatigue resistance, and long service life (Cat®…).

Core Technical Parameters

Item Details
Part Model CAT 1J-6239 Bearing Assembly (Integrated Unit for Tapered Roller Bearings)

Bearing Type Double row/single row tapered roller bearing, including inner ring, outer ring, rollers, cage, some with preload and sealing structure

Material Inner/outer ring and rollers are made of high carbon chromium bearing steel (such as chromium steel), cage is made of stamped steel plate or phenolic resin, balancing strength and toughness

Surface Treatment Rollers and raceways are quenched + ground, HRC 60-64; inner/outer ring raceways are ultra-precision ground to reduce friction and improve wear resistance

Key Dimensions Inner diameter approx. 85-95mm, outer diameter approx. 150-160mm, width approx. 45-55mm (subject to actual product and manual), compatible with corresponding shaft diameter and bearing housing

Compatible Models Loaders 980G/980H, Excavators 330C/330D, Graders 140H/140K, etc., used for gearbox output shafts, drive axle differentials, and final drive supports.

Performance Characteristics: Withstands radial and bidirectional axial loads; shock and fatigue resistant; preload design suppresses lateral movement and vibration; seals protect against mud, water, and dust, suitable for dusty and humid environments.

Structure and Core Functions:

Heavy-duty load bearing: The tapered roller structure is suitable for radial and bidirectional axial composite loads, transmitting high torque from the gearbox/drive axle, suitable for frequent start-stop and shifting impact conditions.

Integrated assembly: Includes inner ring, outer ring, rollers, and cage; some components have seals and preload, eliminating the need for additional components during installation, reducing assembly errors and time.

Precise positioning and force transmission: The tapered rollers contact the raceway line, resulting in uniform contact stress distribution, limiting radial and axial displacement of the shaft, ensuring rotational accuracy and transmission efficiency.

Sealing protection: Features contact/non-contact seals to prevent impurities from entering and grease leakage, suitable for dusty, humid, and temperature-varying operating environments in construction machinery.

Installation and Maintenance Points

Installation Specifications
Clean the journals, bearing housings, and components to remove burrs, rust, and oil stains to avoid damaging the raceways and rollers during installation.

Use hot fitting (heating to 80-100℃) or cold pressing. Do not directly strike the inner/outer rings to prevent deformation or cracking.

Control the preload according to the manual to avoid over-tightening causing overheating or under-tightening causing vibration and wear.

Maintenance Recommendations
Check every 1000-1500 working hours for abnormal noises, abnormal temperature rise, seal failure, and increased clearance. Replace immediately if any issues are found.

Inspect the matching oil seals, bushings, and lock nuts simultaneously. Replace the entire set if wear exceeds limits to prevent rapid failure of new components.

Store in a moisture-proof and impact-proof environment, keeping the raceways and rollers clean and rust-proof.