CAT 528-7158 80.11mm Inner Diameter Sleeve Bearing

CAT 528-7158 (GD, General Duty series) is a Caterpillar bucket/linkage trunnion for construction machinery. It is suitable for the boom-bucket and boom-stick connection hinge points of small and medium-sized excavators/loaders. Its core function is to act as a hinge support and rotation shaft, bearing heavy loads and impact loads, ensuring structural stability and motion accuracy during operation. The following is precise technical and application information:

Core Technical Parameters
Item Details
Part Model: CAT 528-7158 (5287158) GD Trunnion, a general duty hinge shaft, suitable for the hinge points of buckets, linking rods, and boom/stick Cat®…
Core Material: 42CrMo alloy tempered steel, surface hardened + phosphated, tensile strength ≥1000 MPa, yield strength ≥800 MPa, surface hardness HRC 45–50, core hardness HB 280–320
Key Dimensions: Diameter 50.8 mm (2 in), total length 127 mm (5 in), shoulder diameter 63.5 mm, center bore M8×1.25 (lubrication channel), unit weight approx. 0.45 kg (0.99 lb), tolerances: diameter ±0.02 mm, length ±0.1 mm
Suitable operating conditions: Suitable for heavy-duty excavation/loading operations, radial load ≤150 kN, swing angle ±120°, suitable temperature -20℃ to +120℃, suitable for mineral oil-based grease
Compatible models: CAT 305.5E2/306E2 excavators (bucket linkage hinge), 906M/907M loaders (boom-rocker arm hinge), 420F2 bulldozers (blade tilt trunnion)
Accessories: Suitable bushing 603-6178 (straight sleeve bearing), seal ring 374-6512 (seal retainer ring), grease nipple 1J-5322 Core Functions and Structural Features

Heavy-duty Support: Made of alloy tempered steel with surface hardening, it is impact-resistant and fatigue-resistant, adaptable to alternating loads in excavation operations, preventing breakage and deformation.

Precise Articulation: Strict shaft diameter tolerance control, combined with straight sleeve bearings, achieves low-clearance rotation, ensuring the movement accuracy of the bucket/stick and reducing operational deviations.

Long-lasting Lubrication: A central lubrication channel + shaft shoulder sealing groove design allows for grease application via grease nipples, reducing wear on the articulation surfaces and extending service life.

GD Series Advantages: Suitable for non-extreme working conditions, high cost-effectiveness, consistent with original equipment manufacturer (OEM) parts dimensions, meeting routine maintenance and replacement needs (Cat®…).

Installation and Maintenance Points
Installation Specifications: Clean the trunnion, bushing, and mounting holes, removing burrs, oil, and impurities. Mounting hole inner diameter tolerance: +0.05~+0.1 mm; surface roughness: Ra≤1.6 μm.

Use a cold-press method (or heat the bushing to 80–100℃) to avoid scratching the trunnion and bushing. After installation, the shoulder fit gap should be ≤0.05 mm.

After installation, apply lithium-based grease (NLGI Grade 2) to ensure unobstructed lubrication channels. Tighten bolts diagonally to the specified torque (120 N·m for M16 bolts).

Maintenance Recommendations: Apply grease every 500 working hours and check the trunnion play. When the play is >0.5 mm, replace both the trunnion and bushing simultaneously.

Regularly inspect the seals to prevent impurities from entering the hinge surface and causing abnormal wear, thus extending the trunnion’s service life.