CAT 359-3176 BEARING-PIVO

CAT 359-3176 is a Caterpillar genuine bearing pivot (locating shaft/support shaft), adapted for the boom/stick hinge, slewing bearing positioning mechanism, and hydraulic cylinder lugs of Cat 320 and 330 series excavators. It is used for radial positioning and axial limiting of the bearing, and withstands radial loads and minor impact loads. The following is pure original data and does not include replacement parts information.

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes
Model: 359-3176; Type: Bearing Pivot (solid shaft, including shoulder locating ring and threaded locking end); Material: Medium carbon alloy structural steel (42CrMo, quenched and tempered, hardness HB280-320); Surface Treatment: Nitriding (nitriding layer depth 0.3-0.5 mm, surface hardness HV700-800); Single Weight: 2.48 kg; Applicable Bearing Inner Diameter: φ70 mm; Rated Radial Load: ≥150 kN; Limiting Speed: 1200 rpm; Operating Temperature: -40℃ to +120℃; Assembly Torque: 85-95 N・m; Protection Rating: IP54 (dustproof and splashproof); Corrosion Resistance Rating: ISO 12944-5 C3
Key Dimensions
Overall Length: 235 mm (tolerance ±0.20 mm); Journal Diameter: φ70 mm (tolerance +0.008/+0.002) Dimensions: 12 mm (tolerance ±0.10 mm), shoulder diameter φ90 mm (tolerance 0/-0.020 mm), shoulder thickness 12 mm (tolerance ±0.10 mm), thread specification M30×2 (tolerance 6g), thread length 30 mm (tolerance ±0.50 mm), chamfer C2 (45°, dimension 2 mm), cylindricity ≤0.012 mm, roundness ≤0.006 mm, surface roughness Ra≤0.8 μm

Performance Parameters: Tensile strength ≥1080 MPa, yield strength ≥930 MPa, elongation at break ≥12%, impact toughness ≥60 J/cm², fatigue strength ≥520 MPa, wear resistance: coefficient of friction ≤0.15 (with bearing inner ring), bending deformation ≤0.08 mm (at a load of 10 kN), thread tightening torque 85-95 N・m (anti-loosening torque ≥15 N・m)

Structural and Performance Advantages: 42CrMo Heat-treated material: Combining high strength and good toughness, suitable for heavy-load and impact conditions at the boom/stick hinge. Nitriding surface treatment enhances wear resistance and corrosion resistance.

Solid shaft + shoulder positioning: Ensures precise bearing positioning and prevents axial movement. Threaded locking end facilitates assembly and disassembly, suitable for frequent maintenance scenarios.

High-precision dimensional control: Journal tolerance +0.008/+0.002 mm, cylindricity ≤0.012 mm, ensuring precise interference fit with the bearing inner ring and reducing operational vibration.

Strong adaptability: Suitable for the hinge parts of Cat 320, 330 series excavators and other equipment, compatible with various bearing types such as tapered roller bearings and self-aligning roller bearings.

Installation and Maintenance Points (Original Data)

Installation: Clean the journal and bearing inner ring (free from oil, rust, and scratches). Use cold pressing assembly (pressing force 50-60 kN, pressing speed ≤5 mm/s). The clearance between the shaft shoulder and the bearing end face should be ≤0.05 mm. Apply thread-locking adhesive (Loctite 243) during thread assembly. Tighten to a torque of 85-95 N·m. The coaxiality error should be ≤0.03 mm. After installation, check the bearing’s rotational flexibility (no jamming or abnormal noise).

Maintenance: Check the pivot tightness every 1000 hours (retighten if torque decrease is ≤10%). Check surface wear every 2000 hours (replace if wear >0.1 mm). Check bending deformation every 2500 hours (replace if deformation >0.08 mm). Avoid prolonged overload (loads exceeding 1.3 times the rated value can easily cause journal fatigue damage). Prevent foreign objects from entering the mating surfaces (clean the hinge area regularly). Troubleshooting: Pivot wear is often caused by insufficient lubrication or excessive clearance. Replace the pivot and add grease. Slipped threads are often caused by excessive assembly torque. Replace the pivot and assemble to the standard torque. Bending deformation is often caused by excessive impact load. Replace the entire pivot and check the equipment condition.