CAT 4N-5858 Crankshaft Bearing Cap

CAT 4N-5858 (4N5858) is a Caterpillar genuine crankshaft bearing cap, compatible with Cat C15/C18 heavy-duty diesel engines. It is used to secure the main bearing, position the crankshaft, and withstand burst pressure and inertial loads. The following are precise original part information:

Core Parameters and Compatibility Information

Item Details
Part Model: CAT 4N-5858 Genuine Crankshaft Bearing Cap, weighing approximately 4.90 kg (10.80 lb), used in the 3rd/4th main bearing position of C15/C18 engines, positioning the main bearing, securing the crankshaft, and ensuring crankshaft rotation accuracy and bearing preload.

Core Material: High-strength alloy cast iron (ASTM A536 Grade 80-55-06), normalized and tempered, tensile strength ≥552 MPa (80 ksi), hardness HB197-241, toughness and rigidity suitable for high-frequency vibration and high-load conditions in engines.

Key Dimensions Length approximately 203.20 mm (8,000 in), width approximately 101.60 mm (4,000 in), height approximately 76.20 mm (3,000 in), bearing bore diameter approximately 104.78 mm (4.125 in), compatible main bearing outer diameter 104.78 mm, matching cylinder block bolt hole spacing and diameter, locating pin diameter 12.70 mm (0.500 in).

Structural Features: Integral casting, with locating pin hole, bolt hole and bearing seat, precision machined surface, bearing bore roughness Ra≤0.8μm, locating pin precisely positioned with cylinder block to prevent installation misalignment, matching main bearing bearing shell for preload and lubrication.

Compatible Models: Compatible with CAT C15 ACERT and C18 ACERT heavy-duty diesel engines, used in the power systems of construction machinery (such as 988K loaders, 374D excavators) and mining trucks (777D/777F). 4N-0614 Main Bearing Sheet, 10R-7693 Bolts

Matchings: Compatible with CAT 10R-7693 main bearing cap bolts (torque approx. 220-240 N・m), 4N-0614 main bearing sheets (0.05 mm/0.07 mm/0.10 mm, three bearing sheet thicknesses available), 4C-9520 mounting punch, locating pin with cylinder block interference fit (0.01-0.02 mm)

Core Functions and Installation Points

Positioning and Load Bearing: Fixes the main bearing sheet, positions the crankshaft main journal, bears the cylinder explosion pressure and crankshaft inertial load, prevents main bearing loosening or displacement, ensures crankshaft high-speed rotation accuracy, reduces bearing wear, and improves engine reliability.

Installation Specifications: Clean the bearing cap, cylinder block contact surfaces and bolt holes, removing oil and burrs. Inspect the locating pin holes and bearing seats for cracks and deformation, and ensure the bearing sheet mating surfaces are undamaged.

Install the locating pins, apply engine oil to the bearing shells, bolt threads, and seat surfaces. Tighten the bolts to the standard torque in 3-4 steps diagonally, finally turning the bolts 90° to ensure even preload.

After installation, check the crankshaft axial clearance (0.10-0.25 mm) and radial clearance (0.05-0.08 mm). The crankshaft should rotate smoothly without jamming or abnormal noise. The main bearing cap and cylinder block contact gap should be ≤0.02 mm.

Maintenance Recommendations: Every 2000 operating hours, check the bearing cap bolt torque, locating pin condition, and bearing shell wear. Retighten any loose bolts. Replace the bearing shells when the clearance is >0.15 mm. Replace the bearing caps with genuine parts immediately if they are cracked or deformed.

Use only genuine CAT 4N-5858 parts. The alloy cast iron material matches the cylinder block to avoid bearing shell burning, crankshaft wear, or engine failure caused by non-genuine parts with material/dimensional deviations.