Product Descreiption
1. Specifications
- Part Number: 3944679-L (OEM: 3944679)
- Application: Cummins L-series (ISL9, QSC8.3, ISLE) diesel engines
- Material: High-strength alloy steel (quenched & tempered)
- Type: Forged, high-precision bolt with reduced shank (fatigue-resistant)
- Thread: Fine thread (high accuracy)
- Tensile Strength: ≥ 1200 MPa
- Yield Strength: ≥ 1000 MPa
- Tightening Torque: 55–60 N·m + 45° angle (follow OEM specs)
2. Installation Position
- Located at the big end of the connecting rod
- Secures the connecting rod cap to the rod body
- Clamps the connecting rod bearing onto the crankshaft journal
- Quantity: 2 bolts per connecting rod
- 3. Function
- Fastening: Clamps rod cap and rod body tightly to form a rigid big end
- Load Transmission: Transfers gas pressure and inertia forces from piston/rod to crankshaft
- Bearing Retention: Holds the rod bearing in place against the crankpin
- Fatigue Resistance: Withstands cyclic tension, bending, and impact loads during engine operation
- Safety: Prevents separation of rod cap, avoiding catastrophic engine failure
