CAT 490-7434 BUSHING

CAT 490-7434 is a Caterpillar original heavy-duty steel straight bushing, adapted for excavator boom/stick pins and loader bucket hinge points, used for low-speed heavy-duty oscillating conditions. The following are the original core information (no alternative parts available):

Core Technical Parameters (Original Part Exclusive)

Item Details
Part Model: CAT 490-7434 (4907434) Heavy-duty Steel Straight Bushing (Adapted for boom/stick pins and bucket hinge points, withstands radial loads + low-speed oscillation, original design)

Core Material: 20CrMnTi carburized steel (surface hardness HRC 58–62, carburized layer depth 1.2–1.5 mm), 3 axial lubrication grooves in the inner bore (groove depth 0.8 mm), compatible with Caterpillar-specific lithium-based grease (NLGI 2)

Key Dimensions: Inner diameter 70 mm, outer diameter 90 mm, length 60 mm, wall thickness 10 mm mm, inner hole roundness tolerance ≤0.01 mm, mounting surface perpendicularity tolerance ≤0.02 mm
Single weight: Approx. 1.62 kg (3.57 lb)
Compatible models: CAT 336D2/336D2L excavators (boom/stick pins), 980M/982M loaders (bucket hinge), compatible pin model 490-7435, often used with 490-7436 sealing rings
Operating compatibility: Rated radial load 110 kN, limiting speed 1000 rpm, operating temperature -40℃ to +140℃, suitable for low-speed heavy-load swinging conditions
Core functions and structural features (original factory design):
Heavy-duty wear-resistant: Carburized steel surface hardening treatment, suitable for heavy-duty swinging forces of the boom/stick pins, original factory carburized layer depth matches the fatigue life design of the whole machine, impact load resistance up to 150 kN.

Lubrication Optimization: Three axial lubrication grooves in the inner bore ensure uniform grease distribution, reducing the coefficient of friction (f≤0.08) and minimizing adhesive wear between the pin and bushing.

Precise Fit: The clearance with the 490-7435 pin is 0.02–0.03 mm, conforming to Caterpillar’s overall assembly standards, ensuring smooth and unobstructed movement.

Deformation Resistance Enhancement: Integral forging and precision grinding ensures uniform wall thickness (tolerance ±0.01 mm), making it less prone to deformation under heavy loads. Original factory service life exceeds 6000 hours.

Installation and Maintenance Points (Original Factory Specifications)

Installation Specifications: Clean the mounting hole, ensuring it is free of rust, oil, and burrs. The hole tolerance is +0.01–+0.02 mm. Use cold pressing (using a dedicated press tool) with a pressing force of 12–15 kN. Do not strike the end face.

After installation, check the roundness of the inner hole to ensure it is ≤0.01 mm. Control the clearance with the pin to 0.02–0.03 mm to ensure oscillation accuracy.

Use M12×1.5 bolts (8.8 grade) for fastening, with a torque of 55–60 N·m, to prevent axial movement of the bushing.

Maintenance Recommendations: Check the bushing condition every 800 working hours for wear, cracks, and grease leakage. Replace according to original factory standards.

Use Caterpillar-specific lithium-based grease for lubrication, adding 30–40 g each time, ensuring the lubrication groove is full.

When replacing, only genuine CAT 490-7434 bushings must be used. Simultaneously replace the genuine 490-7435 pin and 490-7436 seal to ensure compatibility and service life.