CAT 584-6671 140.35mm Inner Diameter Sleeve Bearing

CAT 584-6671 (5846671) YM is a Caterpillar heavy-duty straight sleeve bearing, commonly known as a “boom/stick hinge sleeve”. It is primarily used in heavy-duty hinge parts such as boom, stick, connecting rod, and cylinder lugs of CAT 320D/323D/330D excavators, 966M/972M loaders, and D6T/D7R bulldozers. It is used to withstand radial heavy loads and impact loads, reduce wear on pins and seat holes, ensure smooth rotation of hinge parts, and is compatible with grease lubrication systems. The following is the core information:

Core Technical Parameters
Item Details
Part Model: CAT 584-6671 (5846671) YM Heavy-Duty Straight Sleeve Bearing
Material: 42CrMo alloy steel, integrally quenched + tempered (HRC 50–58), surface hardening depth 2–3 mm, excellent core toughness, strong impact and deformation resistance
Key Dimensions: Inner diameter 63.5 mm (2.5 in), outer diameter 76.2 mm (3.0 in), length 76.2 mm (3.0 in), wall thickness 6.35 mm, chamfered ends 1×45°
Single Weight: Approx. 0.78 kg (1.72 lbs)
Surface Treatment: Quenched + blackened/oxidized, with axial lubrication grooves and radial oil injection holes, suitable for grease lubrication, reducing friction and wear
Compatible Models: CAT 320D/323D/330D/336GC Excavators, 966M/972M loaders, D6T/D7R bulldozers, 120M/140M graders, etc.

Core Functions: Heavy-duty articulated support, wear-resistant and impact-resistant, suitable for high-frequency oscillating conditions, preventing pin wear and seat failure.

Core Functions and Structural Features:

Heavy-duty adaptability: Made of 42CrMo material with professional heat treatment, compressive strength ≥1200 MPa, capable of withstanding large loads and impacts on the boom, stick, etc., preventing deformation and breakage.

Wear-resistant and anti-galling: Surface hardness reaches HRC 50–58, excellent wear resistance, suitable for harsh working conditions such as dust and mud in construction machinery, preventing seizing and abnormal wear with pins.

Highly efficient lubrication: Equipped with lubrication grooves and oil injection holes, allowing grease to be added through grease fittings to form a stable oil film, reducing the coefficient of friction and extending the service life of bearings and pins.

Easy Assembly: The straight-tube, flangeless design fits stepless seat holes. Chamfered ends facilitate press-fitting, ensuring a tight fit with the seat hole after press-fitting, precise positioning, and guaranteed rotational accuracy.

Installation and Maintenance Points
Installation Specifications: Clean the seat hole and pin, removing burrs, metal shavings, and oil. Seat hole diameter tolerance H7 (76.2 mm + 0.03 mm), roundness ≤ 0.015 mm, surface roughness Ra ≤ 1.6 μm.

Use cold pressing or hot fitting (seat hole heated to 80–100℃). Control the pressing force at 4–6 tons, ensuring the end faces are flush and without tilting. The inner diameter shrinkage after press-fitting should be ≤ 0.04 mm.

After assembly, check the pin’s rotational flexibility for sticking or abnormal noise. Control the radial clearance at 0.06–0.12 mm to avoid uneven wear or seizing caused by abnormal clearance.

Maintenance Recommendations:

Every 200–400 operating hours, add NLGI Grade 2 lithium-based grease until it overflows, ensuring adequate lubrication.

Every 800–1000 operating hours, check for: loose bearings, outer diameter wear >0.1 mm, surface peeling or cracks. Replace immediately if any problems are found.

When replacing, prioritize original equipment manufacturer (OEM) or YM equivalent heavy-duty sleeve bearings to avoid premature failure caused by ordinary steel sleeves.