CAT 549-4322 50mm Inner Diameter Cylindrical Roller Bearing

CAT 549-4322 is a Caterpillar single-row tapered roller bearing (imperial, tapered/cup assembly), suitable for Cat 320D2/336D2 excavator swing gearbox, 966M loader drive axle, C13 engine crankshaft front end, and 140M2 grader rear axle differential. It can withstand heavy radial loads and unidirectional heavy axial loads, and is suitable for medium- and high-speed, high-impact conditions, ensuring stable operation of the transmission system. The following is structured technical and application information:

Core Technical Parameters
Item Details
Basic Attributes
Model 549-4322, Single-row tapered roller bearing (taper/cup assembly), suitable for Cat 320D2/336D2 excavator swing gearbox, 966M loader drive axle, C13 engine crankshaft front end, 140M2 grader rear axle differential, material is chromium-molybdenum alloy steel (inner and outer rings + rollers, carburized and quenched HRC60-64), cage is stamped steel plate (surface phosphated), operating temperature -40℃ to +120℃, single weight approximately 2.6 kg, used to bear heavy radial loads and unidirectional heavy axial loads, suitable for medium-high speed and high impact conditions, preventing shaft movement and wear, ensuring stable operation of the transmission system

Key Dimensions
Inner diameter 82.55 mm (3.25 inches, tolerance 0/-0.015 mm), outer diameter 136.53 mm 5.375 inches (mm), total width 30.16 mm (1.1875 inches), roller large end diameter 22.22 mm, small end diameter 15.88 mm, half cone angle 10°, contact angle 15°, radial clearance C3 (0.08-0.12 mm), mating tolerances inner ring h7 (0/-0.015 mm), outer ring H8 (+0.039/0 mm)
Compatible models: Cat 320D2/336D2 excavators (slewing gearbox, stick cylinder pin), 966M/950M loaders (drive axle, gearbox output shaft), C13 engine (crankshaft front end, balance shaft), 140M2 grader (rear axle differential, steering knuckle)
Assembly fit: Inner ring (cone) interferes with shaft (interference 0.010-0.018 mm) The outer ring (cup) is interference-fitted with the bearing housing (interference 0.008-0.015 mm), suitable for shafts with a diameter of 82.55 mm. The journal fillet radius should be ≤1.5 mm, and the coaxiality ≤0.02 mm. The axial preload after installation is 50-80 N·m. Installation and Maintenance Points: Before installation, clean the bearing cone/cup, journal, and bearing housing bore, checking for scratches, rust, and cracks. Measure the dimensions of the journal and bearing housing bore to ensure the fit meets requirements. The journal fillet radius should be ≤1.5 mm to avoid stress concentration.

Use the cold-press installation method. Use a special press to press the inner ring (cone) into the journal and the outer ring (cup) into the bearing housing respectively. Do not directly strike the inner and outer rings to prevent damage to the rollers and raceways. After installation, adjust the axial preload to 50-80 N·m to ensure no axial movement.

Lubrication and maintenance: For grease lubrication, the filling amount should be 30-50% of the bearing’s internal space (Cat Moly Grease is recommended). For oil lubrication, the oil level must be kept stable. Check the bearing temperature, vibration, and clearance every 800 hours. If the temperature exceeds ambient temperature +40℃, the vibration value is abnormal, or the radial clearance exceeds 0.2 mm, replace the bearing immediately.