CAT 4P-6125 BEARING

CAT 4P-6125 is a Caterpillar single-row tapered roller bearing, suitable for the final drive/differential of Cat D8R/D9R bulldozers and 980G loaders. It is used to withstand heavy radial and unidirectional axial loads and is suitable for low-speed, heavy-duty applications. The following is professional structured information from Cat® Parts.

Core Parameters (Professional Version)

Project Details
Basic Attributes Model 4P-6125, Single-row tapered roller bearing, 2 pieces per unit (paired installation), compatible with Cat final drives/differentials, used for transmitting torque and bearing combined loads, suitable for heavy-duty (≤400 kN) and low-speed (≤1500 rpm) conditions

Key Dimensions Inner diameter 100 mm, outer diameter 180 mm, width 46 mm, cone angle α=12°30′, compatible shaft diameter 100 mm (tolerance m6), bearing housing bore diameter 180 mm (tolerance J7), radial clearance 0.03–0.06 mm, end face runout ≤0.015 mm

Material and Process Material is chromium-molybdenum alloy steel (52100), overall quenching and tempering (tensile strength ≥1000 MPa), raceway surface induction hardening HRC60–64, cage is made of stamped steel plate, rollers are tapered, surface roughness Ra≤0.4 μm
Performance Parameters: Rated dynamic load ≥380 kN, rated static load ≥520 kN, limiting speed (grease lubrication) 1600 rpm, clearance class C2, operating temperature -40℃ to +120℃, permissible axial displacement ≤0.5 mm
Compatible Models: Cat D8R/D9R bulldozer final drive, 980G loader differential, matching bearing housing 423-1992, suitable shaft diameter 100 mm, interference fit with bearing housing 0.01–0.02 mm
Installation and Maintenance Points: Clean the shaft and bearing housing bore before installation. The surface hardness of the bearing housing bore should be ≥HRC30, roughness Ra≤1.6 μm, and free of burrs. Use hot fitting (heating temperature ≤100℃) or cold pressing installation to avoid damage to the rollers and raceways. The rear end face runout should be ≤0.03 mm after installation. The shaft and bearing inner ring have an interference fit (100 mm, m6), while the bearing housing and outer ring have a transition fit (180 mm, J7). Axial clearance should be controlled between 0.05 and 0.10 mm during mating.

Lubrication uses Cat MTO-1000 extreme pressure lithium-based grease, filling to 1/3–1/2 of the bearing cavity volume. Replenish lubrication every 2000 hours; for high-temperature conditions (>80℃), this interval should be shortened to 1200 hours.

Every 3000 hours, check for bearing wear (roller/raceway wear >0.1 mm), temperature rise (>80℃), or abnormal noise. Replace the bearing immediately if any abnormalities are found to prevent bearing seizure and equipment failure.