Product Descreiption
1. Basic Specifications
- Part Number: 3936203‑QSC (also referenced as 3936203, J936203)
- Applicable Engines: Cummins QSC8.3, 4BT, 6BT, 6C series diesel engines
- Pulley Type: Poly V‑belt pulley, 8‑rib K profile
- Pulley Diameter: 73.95 mm (over 2.5 mm balls)
- Pulley Material: Ductile iron
- Construction: Integrated dust shield, spring‑loaded automatic tensioner
- Weight: Approx. 2.7 kg (6 lbs)
- 2. Installation Position
- Location: On the front accessory drive of Cummins QSC8.3 / 4BT / 6BT engines
- Belt Side: Mounted on the slack (non‑drive) side of the serpentine belt
- Belt Routing: Between crankshaft pulley and water pump/alternator pulleys; adjacent to the water pump pulley
- Mounting: Secured to the engine block with 2–3 bolts (M10×1.5)
- 3. Function
- Maintain Tension: Automatically adjusts spring tension to keep the drive belt at optimal tightness, compensating for belt stretch and wear
- Prevent Slippage: Ensures consistent power transfer from crankshaft to accessories (water pump, alternator, fan), avoiding belt slippage, overheating, or charging failure
- Dampen Vibration: Reduces engine‑induced belt vibration and noise, extending belt and accessory life
- Protect Components: Minimizes excessive bearing load on pulleys and accessories, preventing premature wear
