CAT 350-9189 28mm Inner Diameter Seal Bushing

The CAT 350-9189 is a Caterpillar original equipment manufacturer (OEM) sealed sleeve bushing. It integrates load-bearing and sealing/anti-fouling functions, and is suitable for the articulated parts of excavators, load load machines, and other equipment. It is used for radial load bearing, friction reduction and wear resistance, and to prevent dust and oil intrusion. It is compatible with models such as the 320D2/323D2 and 950L/962L, and is suitable for heavy-duty, vibrating, and dusty working conditions.

Core Technical Parameters

Item Details
Part Model: CAT 350-9189 Sealed Sleeve Bushing

Material: Steel back + copper-based alloy / sintered bronze matrix, integrated nitrile rubber (NBR) sealing lips at both ends, molybdenum disulfide coating on the surface, hardness HRC 55-60, oil and wear resistant

Key Dimensions: Inner diameter approx. 65mm, outer diameter approx. 80mm, length approx. 90mm, wall thickness 7.5mm, sealing lip inner diameter 65mm, compatible with 65mm diameter pins, chamfered ends r≈2mm

Compatible Models: Mainstream compatible with 320D2/323D2 excavators, 950L/962L loaders, 430F2 loaders, etc., used for boom/stick hinge points, cylinder lugs, connecting rod bearing seats, and other parts requiring sealing and dust prevention.

Performance Characteristics The one-piece molded sealing structure boasts high load-bearing capacity. The sealing lip prevents dust, water, and oil from entering, ensuring stable operation from -40℃ to 120℃. With grease lubrication, it exhibits low wear, making it suitable for high-frequency reciprocating and low-speed rotating conditions in engineering machinery.

Core Functions and Structure:

Load Bearing and Friction Reduction: Serving as an intermediate support between the pin and the mounting base, it bears radial loads. Sliding friction reduces relative motion resistance between components, lowering wear on the pin and the machine body, and extending component life.

Sealing Protection: The rubber sealing lips at both ends tightly fit the pin, forming a dynamic seal that prevents external dust, water, and oil from entering the friction surface between the bushing and the pin. It also prevents internal grease leakage, reducing lubrication frequency.

Positioning and Guiding: Precise inner and outer diameter dimensions ensure the coaxiality of the pin within the mounting base, preventing uneven wear and guaranteeing the movement accuracy of the hinged parts.

Lubrication Optimization: The inner bore features lubrication grooves and oil holes to store grease, forming an oil film to reduce dry friction and lower maintenance frequency.

Installation and Maintenance Points

Installation Specifications
Clean the mounting hole, bushing, and pin surface to remove oil, rust, and impurities; check that the bushing sealing lip is undamaged and undeformed, and that the mounting hole dimensional tolerances meet H7 requirements.

Use specialized tooling for cold pressing installation; direct hammering is prohibited to prevent bushing deformation and sealing lip damage; after installation, check that the end face fits snugly against the mounting seat without gaps, and that the sealing lip fits tightly against the pin.

Apply lithium-based grease to the pin before installation to ensure sufficient lubrication of the sliding surface and sealing lip; after installation, check rotating parts for any jamming or abnormal noise.

Maintenance Recommendations
Check every 1000-1200 working hours: check for bushing wear and loosening, and ensure the sealing lip is intact. Replace immediately if wear exceeds 0.5mm or the sealing lip is aged and cracked.

Add grease every 250 hours under heavy load/dust conditions, and every 500 hours under light load conditions to avoid dry friction leading to premature wear and sealing lip damage.