CAT 341-9777 BUSHING

CAT 341-9777 is a Caterpillar straight-tube press-fit bushing, adapted for the boom/stick pins and swing platform articulations of Cat 320 and 323 series excavators. It is used to absorb impact, reduce friction, position the pins, and improve the durability and operating accuracy of the articulation parts. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 341-9777, Type: Straight cylindrical flangeless bushing, Material: 42CrMo alloy steel (induction hardened + molybdenum coating), Single weight: approximately 1.2 kg, Applicable temperature: -40℃ to +120℃, Lubrication method: grease lubrication (pre-reserved lubrication channel), Installation method: press fitting, Interference allowance: 0.02-0.04 mm, Matching pin diameter: 50 mm, Surface hardness: HRC 58-62

Key Dimensions
Inner diameter: 50 mm (tolerance H7, +0.030/+0.000 mm), Outer diameter: 65 mm (tolerance r6, +0.040/+0.025 mm), Total length: 80 mm (tolerance ±0.03 mm), Wall thickness: 7.5 mm, Lubrication hole diameter: 4 mm (2 symmetrically distributed), Hole depth: 5 mm, Surface roughness: Ra≤0.8 μm, cylindricity ≤0.008 mm
Compatible Models and Applications: Compatible with Cat 320GC and 323GC excavators, including the lower hinge point of the boom, the upper hinge point of the stick, and the slewing platform connection. Matching parts include a 5P-7582 grease nipple and a 6V-9123 sealing ring for pin guidance and wear protection, reducing impact wear at the hinge joint and extending the life of the pin and structural components.

Performance Parameters: Radial compressive strength ≥1200 MPa, impact toughness ≥80 J/cm², coefficient of friction ≤0.15 (grease lubrication), wear life ≥8000 hours, corrosion resistance meets ISO 9227 neutral salt spray test (48 hours rust-free), can withstand radial static load ≤150 kN, fatigue limit ≥500 MPa

Structural and Performance Advantages: High wear resistance and impact resistance: 42CrMo material + induction hardening + molybdenum coating, balancing surface hardness and toughness, increasing wear life by approximately 3% compared to ordinary carbon steel bushings. This design absorbs high-frequency impacts during boom/stick movements.

Precise positioning and guidance: Strict dimensional tolerances and interference fits prevent radial movement after press-fitting, ensuring pin coaxiality, reducing wear and clearance at hinge points, and improving operational accuracy.

Efficient lubrication: Symmetrical lubrication holes allow for grease injection via grease fittings, forming a continuous oil film, reducing the coefficient of friction, and preventing premature failure due to dry friction.

High versatility: Compatible with key hinge points on multiple 320/323 series excavators, requiring no custom installation tools, facilitating maintenance and replacement, and reducing inventory and maintenance costs.

Installation and maintenance points: Before installation, clean the bushing holes and bushing surface to remove burrs and rust; use a dedicated press-fitting tool (such as 9J-3200) to press vertically, controlling the pressing force to 12-15 kN; after press-fitting, check the end face flatness to ≤0.05 mm to prevent bushing tilting.

Every 500 hours of maintenance, add lithium-based grease (Cat 5P-7582) through the grease fitting, adding only until overflowing. Check the clearance between the bushing and the pin; replace the bushing immediately if the clearance is greater than 0.5 mm to prevent accelerated wear of structural components.

Prioritize original equipment manufacturer (OEM) parts. Aftermarket parts must be guaranteed in terms of material composition, heat treatment process, and dimensional accuracy. Inferior bushings can easily cause pin jamming and structural component damage, increasing maintenance frequency and costs.