Caterpillar C15 Engine Bearings
Core OEM Part Numbers: Main Bearing 4W5698 (STD), 4W5699 (0.050" OS), 243-6718 (Kit); Connecting Rod Bearing 355-8509, 232-3235; Thrust Washer 253-1752; Camshaft Bearing 216-5582 |
Application: Cat C15 / C15 ACERT™ Inline 6-Cylinder Diesel Engine |
Material: Tri-Metal (Steel Back + Copper-Lead + Nickel Barrier + Babbitt) |
Lubrication: Full-Pressure Engine Oil System
Product Overview
Caterpillar C15 engine bearings are precision-engineered, heavy-duty components designed to support the crankshaft, connecting rods, and camshaft under extreme loads, high temperatures, and continuous operation in mining, construction, trucking, and power generation applications. As the critical interface between rotating and stationary engine components, these OEM bearings ensure low friction, reliable oil film retention, and exceptional fatigue resistance—directly impacting engine durability, power output, and uptime. Built to Caterpillar’s strict ISO 9001 manufacturing standards, they are matched to the C15’s 14.6L inline-six architecture (bore 137mm, stroke 171mm) and ACERT™ combustion system.
Core Design & Engineering Features
Material Technology (Tri-Metal Construction)
- Steel Backing: High-tensile cold-rolled steel provides structural rigidity and precise interference fit (0.02–0.05mm) in bearing saddles, eliminating movement and ensuring optimal heat transfer.
- Copper-Lead Intermediate Layer: Offers excellent load-carrying capacity, fatigue resistance, and conformability to minor crankshaft journal irregularities.
- Nickel Barrier Layer: Prevents diffusion between copper-lead and Babbitt, enhancing bond strength and thermal stability at operating temperatures up to 150°C.
- Babbitt Overlay: Soft, lead-tin-based Babbitt (90% Pb, 8% Sn, 2% Sb) provides superior embedability for dirt particles, anti-seizure properties, and low friction under boundary lubrication conditions.
Main Bearing Design
- Split Half Configuration: Upper halves feature precision-drilled oil feed holes aligned with engine block oil galleries; lower halves are plain for maximum load support.
- Thrust Bearing Integration: Main bearing #3 (center) incorporates integral thrust flanges (or paired thrust washers 253-1752) to control crankshaft end play (spec: 0.10–0.25mm).
- Groove Geometry: Optimized circumferential and axial oil grooves ensure consistent oil distribution across the bearing surface, even at low RPM and high load.
Connecting Rod Bearing Design
- Precision-Machined Bore: Matches connecting rod big-end bore with tight tolerances (±0.005mm) for proper crush fit and heat dissipation.
- Lubrication Slots: Precision-cut oil slots align with rod oil passages to deliver pressurized oil to crankpin journals, preventing metal-to-metal contactCat® Parts Store.
- Weight Balanced: Each bearing half is dynamically balanced to within ±0.5g to minimize engine vibration and rotating stress.
Camshaft Bearing Design
- Full-Circle Sleeve Bearings: 7-piece set (216-5582) for camshaft support, featuring a steel-backed aluminum alloy construction for high wear resistance and low friction.
- Oil Hole Alignment: Precision-drilled oil holes match cylinder head oil galleries for consistent lubrication of cam lobes and journals.
Technical Specifications
Main Bearings (Crankshaft)
| Parameter |
Standard Value |
Notes |
| OEM Part Numbers |
4W5698 (STD), 4W5699 (0.050" OS), 243-6718 (Kit) |
Undersizes: 0.020", 0.030", 0.050" |
| Journal Diameter |
104.14mm (4.100") |
Crankshaft main journal |
| Bearing Clearance |
0.038–0.114mm (0.0015–0.0045") |
Critical for oil film formation |
| Crush Height |
0.05–0.08mm |
Ensures tight fit in saddle |
| Thrust Washer |
253-1752 |
Controls end play |
| Material |
Tri-Metal (Steel/Copper-Lead/Nickel/Babbitt) |
OEM specification |
| Max Load Capacity |
120 MPa |
Continuous duty |
| Torque Spec |
180–200 ft-lbs + 115–125° angular rotation |
Multi-stage torque sequence |
Connecting Rod Bearings
| Parameter |
Standard Value |
Notes |
| OEM Part Numbers |
355-8509 (STD), 232-3235 |
Undersizes available |
| Crankpin Diameter |
97.20mm (3.827") |
Connecting rod big end |
| Bearing Clearance |
0.038–0.102mm (0.0015–0.0040") |
Optimized for C15 oil pressure |
| Width |
48.26mm (1.90") |
Matches rod big-end width |
| Material |
Steel-Backed Copper-Lead |
High fatigue resistance |
| Torque Spec |
59–61 ft-lbs + 90° angular rotation |
Rod cap bolts |
Camshaft Bearings
| Parameter |
Standard Value |
Notes |
| OEM Part Number |
216-5582 (7-piece kit) |
Fits C15/C18/C32 engines |
| Journal Diameter |
63.50mm (2.500") |
Camshaft journals |
| Material |
Steel-Backed Aluminum Alloy |
Wear-resistant, low friction |
| Quantity |
7 bearings per engine |
Front to rear support |
C15 Engine Compatibility
- Engine Fitment: Cat C15 (all serial prefixes: 6NZ, 9NZ, MBN, MXS, NXS, SDP, BXS) & C15 ACERT™ (EPA Tier 3/4 Final).
- Lubrication System: Matched to C15’s full-pressure oil system (276–414 kPa / 40–60 psi) for optimal bearing lubrication.
- Crankshaft Configuration: Designed for forged steel crankshaft with 7 main journals and 6 connecting rod journals.
- Emissions Integration: Compatible with ACERT™ fuel injection and EGR systems, ensuring no impact on emissions performance.
Performance & Operational Benefits
- Extreme Durability: Tri-metal construction withstands 24/7 continuous operation, with OEM bearings typically lasting 12,000–15,000 hours in heavy-duty service.
- Superior Load Capacity: Handles peak cylinder pressures up to 180 bar, common in high-horsepower C15 applications (475–580 bhp @ 2100 RPM)Caterpillar Engine.
- Low Friction & Fuel Efficiency: Optimized Babbitt overlay and oil groove design minimize friction losses, improving fuel economy by 2–3% compared to aftermarket bearings.
- Anti-Seizure Protection: Babbitt material provides emergency lubrication during temporary oil pressure drops, preventing catastrophic engine failure.
- Easy Installation: Precision-machined dimensions ensure perfect fit; no modification required for OEM replacement.
Installation & Service Guidelines
Pre-Installation
- Inspect engine block main bearing saddles and connecting rod bores for cracks, wear, or distortion using magnetic particle inspection.
- Verify crankshaft journal diameters and roundness; machine to undersize if worn, and select corresponding undersize bearings.
- Clean all oil passages with solvent and compressed air to ensure unobstructed oil flow.
- Handle bearings with clean gloves; avoid fingerprints or contamination on bearing surfaces.
Installation Steps
- Install main bearings dry (no lubrication on back side) to maintain interference fit; align oil holes with block galleries.
- Torque main cap bolts in sequence (center outward) to 180–200 ft-lbs, then rotate 115–125° (Caterpillar spec).
- Install connecting rod bearings; torque rod bolts to 59–61 ft-lbs, then rotate 90°.
- Measure bearing clearances with Plastigage; confirm values fall within specified ranges.
- Prime oil system and run engine at idle for 10 minutes to establish oil film before loading.
Maintenance Best Practices
- Oil Change Interval: 500 hours with Cat DEO™ CJ-4 or equivalent; contaminated oil is the #1 cause of bearing failure.
- Oil Filter Replacement: Use Cat 1R-0750 filter at every oil change to prevent particle contamination.
- Clearance Inspection: Check bearing clearances during engine overhauls; replace bearings if clearances exceed 0.15mm (0.006").
- End Play Check: Monitor crankshaft end play (0.10–0.25mm); replace thrust washers if out of spec.
Quality & Warranty
- OEM Manufacturing: 100% factory-tested for dimensional accuracy, material composition, and performance; meets Caterpillar’s global quality standards.
- Remanufactured Options: Cat Reman bearing kits (e.g., 243-6718R) use new Babbitt overlays and meet OEM specs, backed by a 12-month/2000-hour warranty.
- Warranty Coverage: New OEM bearings include a 12-month/unlimited hour warranty when installed by an authorized Cat dealer.
Why Choose Cat C15 OEM Bearings?
- Precision Match: Engineered exclusively for the C15 engine, ensuring perfect fit and optimal performance.
- Extreme Environment Design: Withstands high temperatures, vibration, and shock loads in mining, construction, and heavy trucking.
- Global Support: Backed by Cat’s worldwide dealer network for fast delivery, technical support, and warranty service.
- Cost-Effective Reliability: Minimizes downtime and repair costs, delivering the lowest total cost of ownership for C15-powered equipment.
