CAT 322-0641 Bushing

CAT 322-0641 is a Caterpillar heavy-duty straight-tube press-fit steel bushing, suitable for the boom, stick, connecting rod and other hinge parts of excavators, loaders and other equipment. It is used to reduce friction and wear between the pin and the frame, withstand heavy loads and high-frequency oscillations, and ensure the operating accuracy of the equipment and the life of the components. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 322-0641, Type: Straight cylindrical oil-free groove bushing (press-fitted), Material: 4140 alloy steel (carburized and quenched, hardness HRC 60-64), Single weight: approximately 1.25 kg, Operating temperature: -30℃ to +120℃, Design life: ≥10000 hours (normal working conditions), Suitable for heavy-duty, medium-speed oscillation (≤12 times/minute) conditions, Surface treatment: carburized and quenched + precision grinding, Corrosion resistance meets ISO 12944-5 standard, Impact strength: ≥90 J/cm²Cat® Parts

Key Dimensions
Inner diameter: 50 mm (tolerance 0/+0.012 mm), Outer diameter: 65 mm (tolerance 0/-0.018 mm), Total length: 60 mm (tolerance 0/-0.20 mm), Mounting chamfer: r2.0 mm, Wall thickness: 7.5 mm, press-fit interference 0.020-0.030 mm (with mounting hole), clearance with pin 0.012-0.022 mm, locating groove diameter 58 mm (tolerance +0.01/-0.005 mm), radial runout ≤0.01 mm. Compatible models and parts: Compatible with Cat 336D2 and 349D2 excavators, 980M loaders, and other equipment equipped with C9.3 engines. Used for boom and stick hinges, connecting rod pins, bucket trunnions, etc. Matching parts: 16-2153 pins (M12×1.75×65 mm), 5P-0960 extreme pressure lithium-based grease. Can be used in combination with 389-0698 retainers, 135-2443 sealing rings, etc. Compatible bolt type: 12-1982 (M10×1.5×30 mm). (mm)

Performance Parameters: Rated load capacity ≥150 MPa, friction coefficient ≤0.002 (under good lubrication conditions), wear-resistant layer thickness 1.0-1.5 mm, fatigue life ≥6×10⁵ cycles (rated load), sealing surface flatness ≤0.01 mm, radial runout after installation ≤0.01 mm

Structural and Performance Advantages:

Made of 4140 alloy steel with carburizing and quenching treatment, achieving a hardness of HRC 60-64, possessing excellent wear resistance and impact resistance, suitable for the harsh working conditions of heavy-duty and frequent oscillation in engineering machinery, extending component service life.

Precise dimensional tolerances and press-fit interference design ensure stable fit between the bushing and mounting hole, preventing loosening. Simultaneously, the reasonable clearance design with the pin ensures smooth oscillation, reduces frictional resistance, and minimizes energy consumption.

The straight cylindrical structure is suitable for various hinged parts, facilitating easy installation without a complex lubrication system; periodic grease application is sufficient, resulting in low maintenance costs. It is also suitable for compact equipment layouts, simplifying the installation process.

Installation and Maintenance Points:
**Before installation, clean the bushing, mounting holes, and pins, checking for burrs, rust, or deformation. Use a dedicated pressing tool (such as a Cat 9J-3200 press) to smoothly press the bushing into the mounting holes. Do not strike, as this may deform or crack the bushing.**
**After installation, apply appropriate grease to ensure adequate lubrication. Install the elastic retaining ring to secure the pin and prevent axial movement. Before operation, check the hinge joint for smooth movement and any abnormal noises. If any abnormalities are found, adjust immediately.**
**Maintenance:** Check the lubrication and bushing wear every 600 hours. If the clearance exceeds 0.06 mm or scratches or peeling appear on the surface, replace immediately. When replacing, simultaneously check the pin wear. If the pin diameter wear exceeds 0.04 mm, replace it as well. Do not mix bushings of different models.