CAT 380-7378 BEARING-SLV-GD

CAT 380-7378 is a Caterpillar GD series straight sleeve bearing (shoulder sleeve), suitable for the boom, stick and other hinge parts of medium and large excavators and loaders. It is used for pin support, can withstand heavy loads and impact loads, reduce friction and wear, ensure connection accuracy and operational stability, and is suitable for high-frequency oscillating conditions. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 380-7378 (GD Series), Type: Straight-tube sleeve bearing, Material: 4140 low-alloy structural steel (quenched + tempered, hardness HRC 50-55), Surface coated with molybdenum disulfide solid lubricant coating (thickness 0.02-0.05 mm), Single weight approximately 3.2 kg, Operating temperature: -40℃ to +120℃, Load type: radial load + impact load, Lubrication method: grease lubrication (recommended Cat 2 lithium-based grease), Design life ≥12000 hours (normal operating conditions)

Key Dimensions
Inner diameter: 101.6 mm (4 inches, tolerance 0/+0.02 mm), Outer diameter: 120.65 mm (4.75 inches, tolerance 0/-0.015 mm), Overall length: 101.6 mm (4 inches, tolerance 0/-0.1 mm), Wall thickness: 9.525 mm, inner hole surface roughness Ra≤0.8 μm, end face perpendicularity≤0.02 mm, inner and outer circle coaxiality≤0.015 mm
Compatible Models and Parts: Compatible with Cat 336D2 and 349D2 excavators (boom and stick hinge pins, bucket connecting rod pins), 966M loader (boom cylinder lower hinge shaft), with matching 380-7379 seals, 3B-8489 grease fittings, 1J-6472 retaining rings, and 8T-4125 pins
Performance Parameters: Radial rated load 420 kN, allowable linear velocity ≤0.8 m/s, impact load ≥250 kN, coefficient of friction ≤0.1 (grease lubrication), wear resistance ≤0.05 mm/1000 hours
Structural and Performance Advantages: 4140 low alloy structural steel, quenched + Tempering treatment balances core toughness and surface hardness, making it suitable for heavy-load and impact conditions and reducing the risk of fracture and deformation.

A molybdenum disulfide solid lubricant coating reduces dry friction during startup, provides continuous lubrication during long-term use, is suitable for low-speed oscillating conditions, and improves wear resistance.

The straight-tube, flangeless structure facilitates easy installation. The interference fit with the pin and pin hole ensures stable coaxiality of the hinged parts and reduces pin wear.

Installation and Maintenance Points: Before installation, clean the bushing and pin hole, checking for cracks, rust, and deformation. Measure the inner diameter of the pin hole (120.65 mm) and the outer diameter of the bushing, ensuring an interference fit of 0.012-0.028 mm.

Use a hydraulic press and specialized tooling for cold pressing installation. Do not strike the bushing end face. Ensure the end face is flush with the pin hole plane, and that the pin rotates freely without jamming after insertion.

Maintenance: Replenish grease every 1000 hours, check bushing wear. If the inner hole wear is >0.2 mm or the coating peels off or cracks appear, replace immediately. It is recommended to replace it at the same time as the seal and pin.