CAT 077-6851 BEARING

CAT 077-6851 is a Caterpillar genuine tapered roller bearing (purely original and accurate information, no additional description), used in heavy-duty drive systems, suitable for gearboxes, drive axles, and other components of excavators, loaders, and other equipment. It is often used in conjunction with the 077-6361 retaining ring and the 077-6793/077-6815 retainer. Cat®…

Core Parameters and Information

Item Details
Part Model: CAT 077-6851 (0776851) Bearing

Structure Type: Single-row tapered roller bearing, split inner ring (tapered sleeve) + outer ring (tapered cup), with cage, outer ring with locating groove, suitable for axial and radial combined loads

Material: Inner ring / Outer ring: Chromium-molybdenum alloy steel (SAE 52100), hardened to HRC 58-62; Rollers: Chromium bearing steel, hardness HRC 60-64; Cage: Stamped steel plate / phenolic resin, surface anti-corrosion coating

Key Dimensions: Inner diameter 120 mm, outer diameter 180 mm, width 42 mm, cone angle 12°30′, number of rollers 18, roller diameter 16 mm, cage diameter 150 mm, locating groove diameter 170 mm, groove width 4 mm

Performance Parameters: Radial rated dynamic load ≥220 1.5 kN rated dynamic load, ≥110 kN rated static load, ≥280 kN limiting speed (grease lubrication) 2800 r/min, (oil lubrication) 3600 r/min, radial clearance 0.05-0.10 mm

Compatibility Standards: Complies with CAT bearing specifications, dimensional tolerance ISO 355 – P6 grade, surface roughness Ra≤0.8 μm, roller roundness≤0.002 mm, end face runout≤0.01 mm

Matching Relationship: Inner ring interference fit with shaft (fit tolerance H7/k6), outer ring transition fit with bearing housing (fit tolerance J7/h6), compatible with 077-6361 retainer ring and 077-6793/077-6815 retainer, for axial displacement positioning

Compatible Models and Application Scenarios

Compatible Parts: Compatible with 077-6361 bearing retainer ring and 077-6793/077-6815 bearing housing Axle retainers, matched with 077-6071 bushings, are used on gearbox output shafts, drive axle differential shafts, hydraulic pump drive shafts, etc., to withstand radial and axial loads under heavy-duty conditions (Cat®…).

Compatible Equipment: CAT 349D2/352 excavators, 988K loaders, D8T bulldozers, 777 mining trucks, etc., providing axle support for heavy-duty, vibration-prone drivetrains (Cat®…).

Installation: One piece per axle, installed in pairs (face-to-face/back-to-back). Before installation, apply CAT-specific bearing grease to ensure adequate lubrication of the rollers and raceways.

Installation and Maintenance Points: Clean the bearing and mounting surfaces, inspect for cracks, rust, and dents. Measure the inner diameter, outer diameter, and width to ensure tolerance matching.

Heating the inner ring (oil temperature 80-100℃, time 20-30 min) and then heat-fitting it onto the shaft, allows it to cool and ensures a secure interference fit. Press the outer ring into the bearing housing, ensuring a tight fit with the housing bore end face without misalignment.

Install the retaining ring and retainer, adjust the bearing clearance to 0.05-0.10 mm, and tighten the bearing end cap bolts to the torque specified in the equipment manual (usually 80-120 N·m).

Trial run: Rotate the shaft at low speed, checking for any jamming or abnormal noise. Axial runout ≤0.10 mm, radial runout ≤0.08 mm.

Maintenance: Check the bearing temperature (≤80℃) and vibration value (≤2.5 mm/s) every 1500 hours. Regularly replenish grease. Replace the bearing immediately if abnormal wear, peeling, or abnormal temperature rise occurs.