CAT 373-5706 BUSH

CAT 373-5706 is a Caterpillar original integral steel bushing (fitted for boom and stick pins of loaders/excavators, used for radial support and wear protection under low-speed, heavy-load conditions). The following is pure original data and does not include replacement parts information (Cat® Parts).

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes Model 373-5706, type is straight oil-groove-free integral bushing, material is boron steel (quenched and tempered), single weight 1.25 kg, working temperature -40℃ to +120℃, compatible with lithium-based grease (NLGI 2), lubrication method grease lubrication, limiting speed 1000 rpm (grease lubrication), surface treatment is carburizing + quenching + polishing, no sealing structure, rated radial load 120 kN, rated static load 180 kN, fatigue life ≥10000 hours, coefficient of friction μ≤0.009

Key Dimensions Inner diameter 90 mm (3.543 in), outer diameter 105 mm (4.134 in), length 80 mm (3.150 in), wall thickness 7.5 mm, chamfer at both ends r2.5 mm, inner diameter tolerance +0.020/-0 mm, outer diameter tolerance 0/-0.015 mm, length tolerance ±0.15 mm, surface roughness Ra 0.1 μm, carburized layer thickness 0.08-0.12 mm, hardness HRC 58-62
Compatible Models and Parts: Compatible with Cat 966M/972M loader boom linkage pins and 336D2 excavator stick pins. One pin per unit, bearing pure radial load, limiting radial runout, ensuring transmission accuracy and component stability.
Performance Parameters: Radial clearance 0.015-0.025 mm, impact load capacity ≥200 kN, wear resistance ≥6000 hours (normal lubrication), suitable for mineral oil/synthetic hydraulic oil environments, pin mating accuracy H7/h6.
Structural and Performance Advantages: Boron steel material: carburized and quenched, possessing high hardness, high wear resistance, and impact resistance, suitable for harsh working conditions in engineering machinery.

Integrated Design: Seamless construction, high structural rigidity, uniform load distribution, and prevention of early damage caused by localized stress concentration.

Carburized and Polished Surface: Reduces the coefficient of friction, minimizes pin wear, and improves the fitting accuracy and rotational smoothness of the bushing and pin.

Oil-Free Design: Compatible with centralized grease lubrication systems, facilitating grease storage and distribution, and suitable for non-continuously rotating parts such as pins.

Installation and Maintenance Points (Original Data)

Installation: Clean the bushing and mounting base. Use a press-fit method (pressure ≤100 kN) to ensure the bushing end face is flush with the mounting base end face. After installation, radial runout should be ≤0.012 mm. Welding or heat fitting is prohibited (to prevent changes in material properties).

Maintenance: Replenish grease every 500 hours, filling the bushing to 1/3-1/2 of its volume. Check bushing wear every 2000 hours. If inner diameter wear is ≤0.12 mm, normal use is possible; replace if wear exceeds this limit.

Troubleshooting: For jamming during rotation, check the amount and cleanliness of the grease; for abnormal noise, check the fit clearance; for excessive wear, check the material hardness and installation accuracy, replace the bushing in time and repair the relevant parts.