CAT 442-2858 12.725mm Inner Diameter Fastener Sleeve

CAT 442-2858 is a Caterpillar genuine fastener sleeve, designed to fit the disc portion of a hydraulic pump drive shaft. It provides structural support, ensures assembly accuracy, and guarantees transmission stability. The following are precise original factory specifications and application information; replacement parts are not included.

Core Technical Parameters

Item Details
Part Model: CAT 442-2858 (Fastener Sleeve, Precision Machined Carbon Steel Part)

Material: 45# high-quality carbon steel, heat-treated (HB 220-250), blackened surface + rust-preventive oil treatment to improve hardness and wear resistance

Key Dimensions: Inner diameter 12.725 mm (0.501 in), outer diameter 17.48 mm (0.688 in), total length 25.4 mm (1.00 in)

Single Weight: Approx. 0.042 kg (0.093 lbs)

Tolerances: Inner diameter tolerance 0/-0.01 mm, outer diameter tolerance 0/+0.015 mm, length tolerance ±0.05 mm, inner hole surface roughness Ra ≤ 0.8 μm

Performance Characteristics: Tensile strength after heat treatment ≥ 800 MPa, yield strength ≥ 600 MPa MPa, suitable for low to medium speed and medium load drive shaft connection conditions.

Structure and Core Features

Precision Cylindrical Structure: CNC machined from 45# carbon steel, with an inner and outer coaxiality ≤ 0.01 mm, ensuring precise fit with the drive shaft disc and fasteners, avoiding vibration caused by assembly misalignment.

Heat Treatment: Heat treatment gives the sleeve both high strength and good toughness, preventing deformation or breakage during assembly and transmission, suitable for dynamic load conditions of hydraulic pump drive shafts.

Blackening and Rust Prevention Treatment: Blackening the surface forms an oxide protective film, combined with rust-preventive oil, improving rust resistance, suitable for humid environments surrounding hydraulic systems, and extending service life.

Positioning and Support Function: Installed between the fasteners and mounting surface of the drive shaft disc, ensuring precise axial positioning of components, reducing backlash and impact during transmission, and improving transmission efficiency.

Compatible Models and Application Scenarios

Compatible Equipment: CAT hydraulic pump drive shaft assembly (commonly found in core components of hydraulic systems in loaders, excavators, etc., such as the hydraulic pump drive mechanism of 950 and 966 series loaders, and 320 and 325 series excavators).

Core Purpose: Installed on the disc portion of the hydraulic pump drive shaft, it serves as a positioning and support component for fasteners, preventing disc displacement during transmission, reducing vibration and wear, ensuring stable operation of the hydraulic pump, and is suitable for continuous operation conditions in construction machinery.

Installation and Maintenance Points

Installation: Clean the drive shaft disc mounting hole and sleeve surface to remove oil, metal shavings, and check the sleeve for deformation, cracks, and surface damage.

Use the press-fit method for installation. Use a special guide tool to ensure the sleeve and mounting hole are coaxial. Do not directly strike the sleeve end face to avoid affecting the coaxiality of the inner and outer circles.

After installation, check the fit between the sleeve end face and the disc plane. The gap should be ≤ 0.03 mm. Ensure the fasteners are tightened securely.

Maintenance: Regularly (every 500 hours), check the fit between the sleeve and fasteners. If loosening, wear, or corrosion is found, replace the sleeve and tighten the fasteners immediately.

Avoid overload or impact loads to prevent stress concentration from causing the sleeve to break, which could affect the normal operation of the drive shaft and hydraulic pump.

When storing equipment for extended periods, apply rust-preventive oil to the sleeve surface to prevent corrosion caused by humid environments.