CAT 437-2807 BEARING PIST

CAT 437-2807 is a Caterpillar piston pin bushing (piston bearing) suitable for engines such as C9.3 and C13. It is used at the hinge joint between the piston and the small end of the connecting rod, bearing reciprocating impact loads and providing a lubrication channel. It is a key wear-resistant part Cat® Parts that ensures the stable operation of the piston assembly. The following is structured technical and application information:

Core Technical Parameters
Item Details
Basic Attributes
Model 437-2807, Type: Bimetallic Piston Pin Bushing, Material: Steel Back + High Tin Aluminum Alloy (Steel Back Q235, Alloy Layer Tin Content 10-12%), Single Weight: Approx. 0.12 kg, Applicable Temperature: -30℃ to +220℃, Lubrication Method: Pressure Lubrication (Axial Oil Groove + 2 Radial Oil Holes), Installation Method: Interference Fit (Interference Amount 0.025-0.040 mm), Matching Piston Pin 238-8765, Connecting Rod 437-0892

Key Dimensions
Inner Diameter: 45 mm (Tolerance H6, +0.016/+0.000 mm), Outer Diameter: 52 mm (Tolerance s6, +0.040/+0.025 mm), Length: 50 mm (Tolerance ±0.02 mm), Wall Thickness: 3.5 mm, Oil Groove Width: 3 mm Dimensions: mm, oil hole diameter: 3 mm, alloy layer thickness: 0.3-0.5 mm, surface hardness: HB 80-100, cylindricity: ≤0.005 mm, surface roughness: Ra≤0.4 μm. Compatible Engines and Applications: Compatible with Cat C9.3 and C13 engines (loader 966K, excavator 336D2, etc.). Installed between the piston pin hole and the connecting rod small end hole, it transmits the piston reciprocating force to the connecting rod, ensuring free rotation of the piston pin and reducing friction and wear. Matching seal: 437-2808 dust ring. Performance Parameters: Radial compressive strength ≥800 MPa, coefficient of friction ≤0.08 (oil lubrication), wear life ≥6000 hours, corrosion resistance conforms to ISO 9227 neutral salt spray test (no rust after 24 hours), allowable radial load ≤50 kN, fatigue limit ≥300 kN. MPa
Structural and Performance Advantages
**Bimetallic Composite Structure:** The steel backing provides rigid support, while the high-tin aluminum alloy layer offers excellent friction reduction and embedding properties, accommodating minute impurities and preventing scratches on the piston pin and bushing. Wear life is approximately twice that of pure copper bushings.

High-Efficiency Lubrication Design: Axial oil grooves combined with radial oil holes quickly introduce engine oil into the friction surfaces, forming a continuous oil film. This reduces frictional resistance during reciprocating motion and minimizes the risk of adhesive wear under high-temperature conditions.

Precise Interference Fit: Strict dimensional tolerance and interference fit control ensure no loosening after press-fitting, guaranteeing coaxiality between the piston pin and bushing. This prevents increased clearance due to uneven wear and extends the overall lifespan of the piston assembly.

High Adaptability: Designed specifically for C9.3/C13 engines, requiring no modification to the piston or connecting rod structure. This facilitates maintenance and replacement, reducing maintenance costs and downtime.

Installation and Maintenance Points
**Before installation, clean the piston pin bore and bushing surface. Use a dedicated pressing tool to press vertically in, controlling the pressing force to 3-5 kN. After pressing, check the end face flatness to be ≤0.03 mm, ensuring the oil hole aligns with the piston oil passage.**

Every 2000 hours of maintenance, check the bushing and piston pin clearance. The standard clearance is 0.015-0.030 mm. Replace the bushing immediately if the clearance is >0.06 mm. When replacing, simultaneously check the piston pin wear and connecting rod small end bore roundness; replace both if they exceed the standard.

Prioritize original parts. Aftermarket parts must match the material composition and dimensional accuracy. Inferior bushings can easily cause piston pin jamming, connecting rod deformation, leading to abnormal engine noise or even cylinder scoring.