CAT 587-5256 44.45mm Inner Diameter Sleeve Bearing

The CAT 587-5256 is a Caterpillar genuine straight-tube steel-backed sleeve bearing (44.45mm inner diameter, or 1.75 inches). It is suitable for chassis, connecting rods, or working device pins in mini excavators and skid steer loaders. It is used to withstand radial loads, reduce friction and wear, ensure stable rotation between the pin and the pin hole, and is suitable for low-to-medium speed, impact-prone conditions, extending the service life of shafts and structural components.

Cat® 587-5256 is a genuine Caterpillar straight-tube steel-backed sleeve bearing (44.45mm inner diameter, or 1.75 inches). Core Technical Parameters

Item Details
Part Model: CAT 587-5256 (5875256) Straight Sleeve Bearing, no built-in lubrication hole, requires a pin or seat with an oil filling channel, original equipment manufacturer (OEM), no universal replacement Cat®…

Material: Low carbon alloy steel backing + copper alloy wear-resistant layer, surface nitrided (HV 800-1000), compatible with lithium-based grease (NLGI 2 grade), impact resistant, anti-galling, operating temperature -30℃ to 120℃

Key Dimensions: Inner diameter 44.45mm (1.75in), outer diameter 50.8mm (2.00in), length 42mm (1.65in), wall thickness 3.175mm, interference fit 0.012-0.020mm, shaft fit tolerance h6, seat hole fit tolerance H7

Compatible Models: CAT 305.5E2/306E2 For mini excavators, 247B/248B skid steer loaders, and 906M/907M loaders, this product is used for boom link pins, bucket pins, and track tensioner cylinder support pins.

Performance Parameters: Rated radial load 45kN, limiting speed 3000r/min (oil lubrication), coefficient of friction ≤0.12, compatible gear oil viscosity ISO VG 80-140, recommended lubrication every 500 working hours.

Core Functions and Structure:

Radial Load Bearing: The straight cylindrical structure provides uniform circumferential contact, suitable for the radial load of construction machinery pins, preventing shaft bending deformation and ensuring stable oscillation of components such as the link and bucket.

Wear Resistance and Friction Reduction: A copper alloy wear-resistant layer combined with grease reduces friction and wear between the pin and bushing. The steel backing provides high-strength support, suitable for frequent start-stop and sudden load changes, extending the service life of the pin and seat bore (Cat®…).

Positioning Guidance: Precise inner and outer diameter dimensions ensure accurate pin positioning after installation, preventing misalignment during device oscillation and guaranteeing operational accuracy and safety.

Installation and Maintenance Points
Installation Specifications: Clean the journal, housing, and bearing to remove oil and metal shavings. Check the journal surface roughness Ra≤0.8μm and housing roundness ≤0.01mm, ensuring no scratches or rust.

Cold-fit installation (using a special pressure block applied to the bushing end face). Do not strike the wear-resistant layer. After installation, check the fit between the bushing end face and the housing step (gap ≤0.01mm) to ensure unobstructed grease channels.

Maintenance Recommendations: Every 500 working hours, check: grease level, bushing-pin clearance (replace the bushing if clearance exceeds 0.4mm), and for any looseness, wear, or cracks in the bushing.

When replacing, only genuine 587-5256 sleeve bearings should be used. Do not substitute with ordinary steel bushings to avoid premature failure due to material differences.