CAT 603-6178 Straight Sleeve Bearing

CAT 603-6178 is a straight sleeve bearing for Caterpillar construction machinery, suitable for the boom and stick hinge points of mini excavators, loaders, and other equipment, used in low-to-medium load, low-speed swinging applications. The following are the core technology and application information:

Core Technical Parameters Cat®…

Item Details
Part Model CAT 603-6178 (6036178) Straight Sleeve Bearing (Flanged), compatible with pin 603-6179, no lubrication hole design

Core Material Outer layer low carbon steel (1020), inner layer copper-lead alloy (CuPb10Sn10), surface PTFE solid lubricant layer, hardness HB 180–220, coefficient of friction ≤0.12

Key Dimensions Inner diameter 44.45 mm, outer diameter 50.8 mm, length 76.2 mm, wall thickness 3.175 mm, single weight approximately 0.42 kg (0.93 (lb)

Rated Load: Rated radial load 80 kN, suitable for oscillation frequency ≤ 5 times/minute, operating temperature -30℃ to +120℃

Compatible Models: CAT 307E2/308E2 excavators (stick/boom hinge), 907M loader (bucket linkage), 236D3 skid steer loader (boom hinge)

Suitable Working Conditions: Continuous operation under medium to low loads, low-speed oscillation, can withstand slight impacts and vibrations

Core Functions and Structural Features:

Composite Layer Self-Lubricating: Inner layer copper-lead alloy + PTFE solid lubrication layer, suitable for temporary operation in oil-free or low-oil conditions, reducing hinge friction and wear, and extending component life.

Stable Interference Fit: Interference fit with seat bore (interference amount 0.015–0.03 mm), radial runout ≤ 0.03 mm after installation, ensuring smooth operation and preventing loosening.

Highly adaptable: Compatible with various small and medium-sized Caterpillar bearing hinges, with a standard operating life exceeding 5000 hours, wear-resistant and corrosion-resistant.

Installation and Maintenance Points

Installation Specifications: Clean the seat bore and bearing surface, ensuring it is free of oil, rust, and impurities. Use cold pressing, controlling the pressing force to 10–15 kN. Do not strike the end face.

Seat bore tolerance: +0.01–+0.025 mm. After installation, check the inner diameter roundness to ≤0.015 mm. Apply NLGI 2 lithium-based grease.

Maintenance Recommendations: Check the operating status every 500 working hours, looking for looseness, abnormal noise, and leaks.

Replace when the inner diameter wear exceeds 0.18 mm or the surface lubricant layer peels off. Replace the bearing along with the matching pin and dust ring to ensure proper fit.