CAT 233-3248 Steering Control Plastic Bushing

CAT 233-3248 is a wear-resistant steel bushing for Caterpillar hydraulic cylinders/connecting rods. It is compatible with the boom cylinder pins of 320D/336D excavators, the bucket connecting rods of 966K loaders, and the rocker arm shafts of C7.1 engines. Its core function is to reduce friction and wear between the pins and mounting holes, bear radial loads and provide positioning, ensuring smooth operation and stable function of Cat® Parts components. The following is structured technical and application information:

Core Technical Parameters
Item Details
Basic Attributes
Model 233-3248, steel bushing (fixed type, with oil reservoir), compatible with Cat 320D/336D excavator boom cylinder pin, 966K loader bucket connecting rod, C7.1 engine rocker arm shaft, material is 40Cr alloy steel (quenched and tempered HRC 28-32), surface hardened + hard chrome plated (thickness 0.05-0.10 mm, hardness HV 800-1000), working temperature -40℃ to +120℃, single weight approximately 0.35 kg, radial load ≥25 kN, used to reduce friction and wear between the pin and the mounting hole, bear radial load, position components, prevent abnormal wear and jamming of the shaft system, and ensure smooth operation and stable running of hydraulic cylinders, connecting rods and other components.

Key Dimensions
Inner diameter 50.80 mm (2 inches, tolerance) H7 (+0.030/0 mm), outer diameter 63.50 mm (2.5 inches, tolerance h6, 0/-0.019 mm), total length 76.20 mm (3 inches, tolerance ±0.10 mm), oil reservoir width 5.00 mm (tolerance ±0.10 mm), oil reservoir depth 1.00 mm (tolerance ±0.05 mm), inner bore and shaft fit tolerance k6 (+0.018/+0.001 mm), cylindricity ≤0.01 mm
Material and process: 40Cr alloy steel → forging → quenching and tempering (860℃ oil quenching + 560℃ tempering) → precision turning → surface hardening (HRC 58-62) → hard chrome plating → precision grinding → inspection. It possesses high wear resistance, fatigue resistance, and corrosion resistance, suitable for reciprocating/oscillating applications such as hydraulic cylinders and connecting rods, reducing friction and wear, and extending the service life of pins and mounting holes.
Compatible models: Cat 320D/336D Excavators (Boom Cylinder Pins, Stick Cylinder Pins), 966K Loaders (Bucket Connecting Rods, Boom Connecting Rods), C7.1 Engines (Rocker Arm Bushings), 140M Graders (Scraper Cylinder Pins)

Assembly Fit: Compatible with 50.8 mm diameter pins (tolerance k6, +0.018/+0.001 mm), mounting hole diameter 63.50 mm (tolerance H7, +0.030/0 mm), pin clearance 0.010-0.025 mm, end face contact area with mounting surface ≥95%, oil reservoir connected to lubrication system to ensure adequate lubrication.

Installation and Maintenance Points: Before installation, clean the bushing, pin, and mounting hole. Check for scratches, rust, and cracks. Measure the inner diameter of the bushing and the pin diameter, and the outer diameter and the mounting hole diameter to ensure the fit meets requirements. Pin fillet radius ≤2.0. To avoid stress concentration, ensure the bushing is installed using a press-fit method, ensuring it is coaxial with the mounting hole. Do not strike directly with a hammer to prevent bushing deformation. After installation, check the clearance between the bushing and the pin, ensuring it is within the range of 0.010-0.025 mm to guarantee smooth component operation.

Maintenance Recommendations: Check the bushing’s wear and lubrication condition every 1500 hours. If the inner diameter wear is >0.10 mm or scratches or peeling appear, replace immediately. Regularly replenish lubricating grease (Cat Moly Grease recommended) to prevent abnormal wear of the bushing and pin due to insufficient lubrication, which can affect the component’s lifespan.