CAT 8J-7651 BEARING

CAT 8J-7651 is a Caterpillar original single-row radial ball bearing, suitable for the gearbox, reducer, or lifting mechanism of 3306 engines and wheeled tractor loaders (such as 615C, 633E). It is used for rotational support and positioning under low-to-medium speed and light load conditions. The following is pure original data and does not include replacement parts information.

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes
Model 8J-7651, Type: Single-row deep groove ball bearing (open, unsealed), Suitable for engine accessory drives, gearbox shifting mechanisms, and lifter gearboxes; Weight: 0.1 kg; Operating temperature: -40℃ to +120℃; Suitable for lithium-based grease; Used in rotating parts with predominantly radial loads to reduce friction, position rotating parts, and improve transmission smoothness.

Key Dimensions (Metric/Imperial)
Inner diameter: 38.1 mm (1.5 in), Outer diameter: 69.85 mm (2.75 in), Width: 15.88 mm (0.625 in), Chamfer: 1×45°, Suitable shaft diameter tolerance: h6, Seat bore tolerance: H7, Mounting clearance: 0.01-0.03 mm, Suitable mounting space: Diameter ≥72 mm, Thickness ≥17 mm

Performance Parameters
Ring material: GCr15 bearing steel, Hardness: HRC 61-65, 8 mm diameter steel balls, 10 balls, cage made of reinforced nylon, radial dynamic load rating 18.5 kN, radial static load rating 10.2 kN, limiting speed (grease lubrication) 8000 rpm, suitable speed ≤5000 rpm, wear life ≥6000 hours, can withstand slight axial movement loads.

Structure and Compatibility Characteristics:
Open single-row design: No built-in seal, requires external oil seal. Suitable for gearboxes, reducers, and other parts with built-in lubrication systems, facilitating grease replenishment and reducing maintenance costs.

Light load, high speed compatibility: Deep groove ball bearing structure is suitable for radial light load and medium-to-high speed rotation conditions. Applicable to engine accessory drives, shifting mechanisms, and other speed-sensitive parts with low loads, ensuring rotational accuracy and stability.

Universal Compatibility: Compatible with the lifting linkage mechanism and speed reducer of wheeled tractors and loaders such as the 3306 engine, 615C, 615C II, and 633E. It supports and positions the rotating shaft, preventing friction and wear caused by shaft misalignment.

Installation and Maintenance Points (Original Data)

Installation: Clean the shaft and seat hole (free of oil and metal shavings). Assemble by cold pressing or hot fitting (shaft temperature ≤80℃), ensuring the bearing end face fits snugly with the positioning surface. Coaxiality ≤0.05 mm. After installation, rotate by hand without jamming. Radial clearance 0.015-0.025 mm.

Maintenance: Check lubrication and wear every 1500 hours. Regularly replenish lithium-based grease (every 500 hours). Replace bearings immediately if abnormal noise, clearance ≥0.10 mm, or surface pitting occurs to prevent shaft vibration and damage.