Diesel Engine Parts, Products

🔧 Specifications

• Part Number: 3950135 (replaced by 5284141)
• Application: Cummins ISLE, QSL9, 6L8.9 diesel engines
• Material: High‑strength alloy steel, heat‑treated for wear resistance
• Teeth: 84 teeth
• Bore: 25 mm (keyway fit)
• Dimensions: Approx. φ250 × 56 mm
• Type: Timing gear, precision machined with timing marks

📍 Installation Position

• Mounted on the front end of the camshaft, inside the engine timing gear housing (front cover).
• Meshes with the crankshaft gear (and idler gears) in the timing train.
• Installed via keyway + press fit; secured by bolts (torque per Cummins specs).
• Critical: align timing marks with crankshaft gear to ensure correct valve‑to‑piston timing.

⚙️ Function

1. Timing Synchronization: Drives the camshaft at 1/2 crankshaft speed (4‑stroke engine), ensuring precise valve timing.
2. Power Transmission: Transfers rotational force from the crankshaft to the camshaft, actuating the valvetrain.
3. Valve Control: Ensures intake/exhaust valves open/close at the exact right moment for combustion, efficiency, and power.
4. Engine Protection: Prevents valve‑piston collision and performance loss due to incorrect timing.