Cummins engine spare parts Inert gear C4327556 in stocked

Crafted from 42CrMo alloy steel—an industry standard for high-torque engine gears—the inert gear delivers exceptional mechanical performance: a minimum yield strength of 800 MPa, a tensile strength of 1,000 MPa, and a Brinell hardness of 280–320 HB. This material undergoes a strict heat treatment process (quenching at 850°C followed by tempering at 550°C) to enhance hardness and toughness, enabling it to withstand continuous torque loads of up to 500 N·m—surpassing the maximum operating torque of Cummins X15 engines (450 N·m). Compared to standard carbon steel gears, 42CrMo alloy steel reduces the risk of gear tooth deformation or fracture by 60% under extreme conditions (e.g., sudden load spikes during heavy acceleration), ensuring long-term reliability in high-demand applications

The gear features a hobbed and ground involute tooth profile (module 3.5, pressure angle 20°) with a tooth count of 40—machined to AGMA (American Gear Manufacturers Association) Class 10 precision standards. This high-precision design ensures a contact ratio of 1.8 (vs. 1.2 for lower-class gears), distributing load evenly across multiple teeth and reducing tooth stress by 35%. The tooth surface is finished with a superfinishing process (Ra ≤0.8μm), minimizing friction between meshing gears and lowering operating noise to ≤65 dB (measured at the engine timing cover). Additionally, the gear’s root fillet radius (2.5mm) is optimized to prevent stress concentration—a common failure point in poorly designed gears—extending the component’s fatigue life to 10,000 operating hours (equivalent to 800,000 km of truck operation)

To combat wear and corrosion in engine environments (exposed to oil, coolant, and temperature fluctuations), the inert gear undergoes two key surface treatments:

Carburizing & Nitriding: The tooth surface is carburized to a depth of 0.8–1.2mm (hardness up to 60 HRC) and then nitrided to form a 50μm-thick wear-resistant layer, reducing tooth wear by 50% compared to uncoated gears.

Phosphating & Oil Dipping: The gear’s non-tooth surfaces are phosphated (forming a 10μm zinc phosphate layer) and dipped in high-temperature engine oil (SAE 15W-40), providing corrosion resistance (passing 48 hours of salt spray testing) and ensuring immediate lubrication upon engine startup.

These treatments make the gear suitable for extended service intervals (up to 50,000 km between oil changes), reducing maintenance frequency and costs for fleet operators

Designed for hassle-free installation by engine technicians, the inert gear features user-friendly details that simplify maintenance:

Precision Machined Mounting Holes: Four 8mm-diameter mounting holes (spaced 60mm apart) are drilled to H7 tolerance (±0.015mm), ensuring perfect alignment with the engine’s timing cover bolts and eliminating the need for reaming or adjustment.

Clear Timing Marks: Laser-etched timing marks on the gear’s face align with corresponding marks on the crankshaft and camshaft gears, enabling quick and accurate timing setup (reducing installation time by 40% vs. unmarked gears).

No Special Tools Required: The gear can be installed using standard hand tools (a 14mm socket for mounting bolts, a gear puller for removing the old component), with no need for specialized gear pressing equipment.

Installation typically takes 90–120 minutes: remove the engine timing cover, detach the old inert gear, align the new gear’s timing marks, torque the mounting bolts to 25 N·m (per Cummins specs), and reinstall the timing cover. Each unit undergoes dimensional inspection via CMM (Coordinate Measuring Machine), gear tooth profile testing, and hardness verification, backed by a 24-month warranty against defects (e.g., tooth fracture, excessive wear, coating peeling)