CAT 177-2499 BEARING AS

CAT 177-2499 is a Caterpillar genuine tapered roller bearing assembly, suitable for high-speed, heavy-duty components such as the hydraulic pump drive shaft and slewing gearbox input shaft of Cat 320D2/323D2 excavators. It is used for radial and bidirectional axial load bearing. The following is pure original data and does not include replacement parts information.

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes
Model 177-2499, Type: Double row tapered roller bearing assembly (including inner ring, outer ring, rollers, cage, and seals), Material: Inner ring/outer ring/rollers are high-carbon chromium bearing steel (GCr15SiMn, quenching hardness HRC 61-65), Cage is phenolic resin reinforced with cloth (high strength and wear resistance), Seal is nitrile rubber (NBR, oil-resistant and high-temperature resistant), Single weight 3.2 kg, Applicable shaft diameter φ70 mm, Rated radial load ≥220 kN, Rated axial load ≥180 kN, Operating temperature -30℃ to +120℃, Lubrication method: Grease lubrication (recommended lithium-based grease, dropping point ≥180℃), Protection class IP65, Assembly interference 0.012-0.025 mm

Key Dimensions
Inner diameter φ70 mm (tolerance +0.015/+0.005 mm), Outer diameter φ125 mm (tolerance 0/-0.02 mm), width 45 mm (tolerance ±0.15 mm), roller large end diameter φ18 mm (tolerance ±0.02 mm), roller length 28 mm (tolerance ±0.10 mm), cone angle 15° (tolerance ±1°), roundness ≤0.01 mm, cylindricity ≤0.012 mm, end face parallelism ≤0.02 mm
Performance parameters: Dynamic rated load Cr=225 kN, static rated load C0r=280 kN, fatigue life ≥10000 hours (rated load cycles), coefficient of friction ≤0.003 (grease lubrication, speed ≤1500 rpm), limiting speed grease lubrication 1600 rpm, oil lubrication 2200 rpm, impact toughness ≥25 J/cm² (-20℃), roller surface roughness Ra≤0.04 μm Structural and Performance Advantages

Double-row tapered design: Can withstand radial and bidirectional axial loads simultaneously, suitable for complex stress conditions of hydraulic pump drive shafts, improving operational stability.

Phenolic resin cage: High strength, low friction, effectively reduces friction and heat generation between rollers, suitable for high-speed rotation conditions.

Nitrile rubber seal: Good oil resistance and high temperature resistance, prevents grease leakage and foreign matter ingress, extending bearing life.

Precision heat treatment process: High-carbon chromium bearing steel is quenched to ensure high hardness and wear resistance, suitable for heavy-load and high-frequency impact conditions.

Installation and Maintenance Points (Original Data)

Installation: Clean the journal and bearing housing bore (free from oil/rust/impurities). Use the hot-fit method (heat the bearing to 80-90℃ before fitting the journal). After installation, check that the gap between the bearing end face and the shaft shoulder is ≤0.05 mm. Preload torque is 80-100 N·m. Do not strike the bearing body. Do not heat to above 120℃.

Maintenance: Replenish grease every 800 hours (1/3-1/2 of the bearing cavity volume). Check bearing clearance every 1500 hours (radial clearance 0.03-0.05 mm is normal; >0.08 mm requires replacement). Check roller and cage wear every 2500 hours (replace bearings if roller surface peeling or cage deformation is observed). Avoid prolonged overload (load ≤ 80% of rated load) and prevent foreign objects from entering the bearing.

Troubleshooting: Excessive clearance is usually due to excessive wear; replace the bearing assembly. Abnormal overheating is usually due to insufficient lubrication or excessive preload; replenish grease or adjust the preload. Roller peeling is usually due to foreign objects entering or excessive installation coaxiality error; replace the bearing and clean the mounting surface.