CAT 4N-5857 215.9mm Long Crankshaft Bearing Cap

CAT 4N-5857 is a genuine Caterpillar crankshaft bearing cap, used for positioning and locking the crankshaft main bearings/connecting rod bearings in heavy-duty diesel engines such as the Cat C13 and C15. The following is the original data and does not include information on replacement parts.

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes
Model 4N-5857, Type: Split Crankshaft Bearing Cover, Material: 42CrMo Alloy Steel (Quenched and Tempered, Surface Phosphated for Corrosion Protection), Weight: 4.2 kg, Applicable Operating Conditions: Engine crankshaft main bearing/connecting rod bearing positioning, Operating Temperature: -40℃ to +220℃, Protection Rating: IP67, Compatible with Cat C13 and C15 Engines, Rated Tensile Strength ≥1080 MPa, Yield Strength ≥930 MPa, Hardness: HRC 28-32, Positioning Accuracy: GB/T 1184-2011 H7 Grade

Key Dimensions (Imperial/Metric)
Mounting Hole Diameter: φ14.00 mm (Tolerance 0/+0.012 mm), Bearing Hole Diameter: φ75.00 mm (Tolerance 0/-0.015 mm), Length: 120.00 mm (Tolerance ±0.05 mm), Width: 85.00 mm (tolerance ±0.05 mm), Height 50.00 mm (tolerance ±0.05 mm), Locating pin diameter φ8.00 mm (tolerance 0/-0.008 mm), Bolt hole center distance 100.00 mm (tolerance ±0.02 mm)

Performance Parameters: Bolt preload torque 180-200 N・m (Grade 12.9 bolts), fatigue life ≥10⁶ cycles, sealing adapter nitrile rubber O-ring (inner diameter φ75 mm, wire diameter 2.65 mm), locating pin clearance 0.010-0.020 mm, bearing hole roundness ≤0.005 mm

Structural and Performance Advantages: High-strength alloy steel material: 42CrMo, quenched and tempered, providing sufficient support strength to withstand alternating loads during crankshaft operation and prevent deformation.

Precise Positioning Design: Equipped with locating pin holes, it precisely matches the engine block, ensuring the coaxiality of the crankshaft bearings and reducing crankshaft wear.

Phosphating Anti-corrosion Treatment: The surface phosphate layer resists salt spray for ≥72 hours, preventing corrosion of internal engine oils and extending service life.

Reliable Sealing: Adapts to O-ring seals to prevent oil leakage and ensure the normal operation of the engine lubrication system.

Installation and Maintenance Points (Original Data)

Installation: Clean the mating surfaces of the bearing cap and cylinder block (free of oil stains and burrs). Before installation, check the roundness and coaxiality of the bearing holes. After installing the locating pins, insert the bearing cap and tighten the bolts symmetrically and evenly (tightening in 3 stages to the pre-tightening torque). After installation, the gap between the bearing cap and cylinder block mating surfaces should be ≤0.02 mm, and the crankshaft should rotate freely without jamming.

Maintenance: Check the bolt torque every 2000 hours. If the torque decreases by more than 10%, retighten. Regularly check the oil pressure. If the pressure drops abnormally, check the bearing cap seal and bearing wear. For long-term storage, apply anti-rust oil and seal to prevent moisture.

Troubleshooting: Common faults include loose bolts, oil leaks, and worn bearing holes, often caused by insufficient installation torque, aging seals, or crankshaft vibration. It is necessary to replace the bearing caps and seals and check the condition of the crankshaft to ensure installation accuracy.