CAT 455-2281 Tilt Cylinder Bush Bearing

CAT 455-2281 is a Caterpillar steel-backed bronze + PTFE composite material bearing bushing, suitable for the boom pin, stick pin, bucket pin and other hinge parts of Caterpillar 320D/336D excavators, 966K loaders, 140M graders and other models. Its core function is to reduce friction between the pin and the pin hole, absorb impact and compensate for clearance, extend the service life of the hinge parts and prevent looseness and abnormal noise. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 455-2281, steel-backed bronze + PTFE composite bearing bushing, compatible with 320D/336D excavator boom pins, 966K loader boom pins, 140M grader bucket pins, material is low carbon steel back + bronze layer + PTFE coating, operating temperature -40℃ to +120℃, single weight approximately 1.25 kg, suitable for grease lubrication (lithium-based grease NLGI 2), rated radial load ≥100 kN, wear life ≥8000 hours, used for friction reduction and impact absorption at hinge joints, preventing wear of pins and pin holes

Key Dimensions
Inner diameter 60.00 mm (2.362 in, tolerance H7, +0.030/0 mm), outer diameter 75.00 mm (2.953 in, tolerance H7, +0.030/0 mm), S6 (+0.053/+0.038 mm), total length 80.00 mm (3.150 in, tolerance ±0.15 mm), chamfered ends C2.0 mm, inner hole roughness Ra≤0.8 μm, clearance fit with pin shaft 0.05-0.10 mm, interference fit with pin hole 0.025-0.040 mm, suitable for standard pin shaft diameter 60 mm.

Material and Manufacturing Process: Low carbon steel backing (Q235, tempered HB 180-200) → Bronze layer centrifugal casting → PTFE coating (thickness 0.01-0.02 mm) → precision turning → drilling (oil reservoir φ2 mm, spacing 15 mm) → precision grinding. It possesses good load-bearing capacity, wear resistance, and self-lubricating properties, suitable for heavy-duty, low-speed oscillating conditions.

Compatible Machines: Cat 320D/336D excavators, 966K/972M This product is suitable for loaders, 140M/160M graders, and 420D/420F backhoe loaders. It is used for articulated parts such as the boom, stick, and bucket, and is compatible with boom pins, stick pins, and bucket pins. It reduces friction, buffers impact, compensates for clearances, and prevents abnormal wear between the pin and pin hole.

Assembly Fit: Compatible with 60 mm diameter pins (tolerance h6, 0/-0.019 mm), with an interference fit of 0.025-0.040 mm with the pin hole. Pressing force: 4-6 tons. Rear end face runout ≤0.10 mm, coaxiality ≤0.05 mm. After press-fitting, the oil reservoir must be aligned with the lubrication channel.

Installation and Maintenance Points: Before installation, clean the bushing, pin hole, and pin. Check for scratches, rust, and burrs. Measure the outer diameter of the bushing and the inner diameter of the pin hole, and the inner diameter of the bushing and the outer diameter of the pin to ensure the fit meets requirements. The surface roughness of the pin hole Ra ≤1.6. μm, with a flat, undeformed end face.

Use a cold pressing method (using a dedicated pressing tool) to vertically press the bushing into the pin hole, ensuring the bushing end face is flush with the pin hole end face. Do not strike directly with a hammer to prevent the bronze layer from peeling off or deforming. After pressing, check that the oil reservoir is clear and aligned with the lubrication channel.

Maintenance Recommendations: Check the bushing wear every 1000 hours. If the inner diameter wear is >0.25 mm or loosening or abnormal noise occurs, replace immediately. Apply lithium-based grease every 250 hours daily to ensure adequate lubrication and avoid dry friction that could accelerate wear.