CAT 6R-4352 Tension Bushing

CAT 6R-4352 is a steel-backed copper alloy wear-resistant bushing used by Caterpillar for articulated parts of construction machinery. It is primarily adapted to the pin joints of equipment such as excavators and loaders, bearing radial loads and providing low-friction sliding support. It is suitable for medium-low speed, medium-heavy load and impact conditions, and is a key component to ensure the flexible operation of articulated parts and extend the life of pins. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 6R-4352, Type: Steel-backed copper alloy bushing (oil-free self-lubricating, with oil reservoir), Material: Steel back + high-strength brass alloy layer (lead-containing, enhancing wear resistance and anti-galling), Single weight: approx. 0.85 kg, Suitable temperature: -20℃ to +120℃, Surface treatment: anti-rust oil coating, Installation method: interference fit + end face positioning

Key Dimensions
Inner diameter: 70 mm (tolerance H7, 70.000-70.030 mm), Outer diameter: 85 mm (tolerance g6, 84.975-84.990 mm), Length: 50 mm (tolerance ±0.2 mm), Wall thickness: 7.5 mm, Inner hole: 3 axial oil reservoirs, Suitable shaft diameter: 70 mm (tolerance k6), Mounting hole diameter: 85 mm (tolerance H7)

Suitable Models and Locations
Suitable for: Cat 320D/323D excavator boom pin bushing, 950GC loader boom linkage bushing, 420F2 bulldozer bucket articulation sleeve, one piece per pin, used to bear pure radial loads, suitable for swing angle ≤ ±35° and linear velocity ≤ 0.8 m/s.

Performance Parameters: Load capacity (static) 150 MPa, (dynamic) 100 MPa; Coefficient of friction (dry) 0.15-0.20, (oil lubrication) 0.09-0.12; Wear life ≥ 10000 hours (under rated load); suitable for extreme pressure lithium-based grease and other lubricants; can work stably in dusty and muddy conditions.

Structural and Performance Advantages:
Durable composite material: The steel backing provides high strength and rigidity, while the brass alloy layer has good wear resistance and impact resistance, effectively absorbing vibration and reducing wear on the pin and bushing, suitable for heavy-duty and impact conditions.

Oil reservoir design: The axial oil reservoir in the inner bore stores grease, maintaining lubrication even during intermittent lubrication, extending maintenance cycles, and reducing friction loss.

Stable interference fit: The outer diameter tolerance g6 fits the mounting hole H7 with an interference fit of 0.010-0.055 mm, ensuring no looseness after installation, guaranteeing positioning accuracy, and preventing the bushing from rotating within the hole.

Good anti-galling performance: The copper alloy layer contains lead, which forms a lubricating film under boundary lubrication conditions, preventing metal-to-metal seizing with the pin, suitable for frequent start-stop and oscillating conditions.

Installation and maintenance points: Before installation, clean the shaft and mounting hole, removing burrs and oil stains. Check the inner bore of the bushing for damage and ensure the alloy layer is not peeling off. Use the cold pressing method (using a special mounting sleeve) to ensure the end face fits snugly against the mounting surface without misalignment, and the interference fit meets requirements.

Lubrication and Adaptation: Apply Cat 2V-9130 extreme pressure lithium-based grease upon initial installation. Replenish every 800 hours, filling to half the bearing clearance. Avoid overfilling, which could damage the seals.

Maintenance every 1500 hours: Check bushing clearance (replace if ≥0.3 mm) and surface wear (replace if depth >0.4 mm). If abnormal noise, jamming, or loose pins occur, replace immediately to prevent component damage.

Prioritize genuine parts. Aftermarket parts may have substandard material composition, dimensional deviations, etc., easily leading to premature wear, excessive clearance, and affecting equipment operating accuracy.