Rocker Arm Assembly 12420479 (Genuine DEUTZ/MWM Part)

1. Basic Information

• Part Number: 12420479
• Name: Rocker Arm Assembly
• Brand: DEUTZ / MWM
• Applicable Models:
  
  
  DEUTZ MWM TBG/TCG 2020/2032 series gas engines
  
  
  DEUTZ TCG 620 V12/V16/V20 series
  
  
  BF6M1013, BF4M2012 industrial, power generation and marine engines
• Applicable Valves: Universal for intake and exhaust valves (valve stem diameter: φ8 mm)
• Function: Core component of the valve train, transmitting thrust from the camshaft to drive valve opening and closing.

2. Material & Manufacturing Process

• Main Body Material: Alloy cast iron / Ductile iron, featuring high strength, high rigidity and excellent impact resistance.
• Bushing Material: Copper-tin based alloy (CuSn) with self-lubricating property, outstanding wear resistance and low friction.
• Heat Treatment: Overall quenching and tempering plus high-frequency quenching on working surfaces. Hardness: HRC 52–58.
• Surface Treatment: Black oxide / Phosphating for rust prevention and resistance to oil and gas corrosion.
• Operating Temperature: -40℃ ~ +450℃, suitable for high-temperature service of gas engines.

3. Key Dimensions (Original Standard)

• Rocker Ratio: 1.75:1, amplifying cam lift to increase valve opening stroke
• Shaft Diameter (Bushing Inner Diameter): φ16 mm
• Fitting Clearance between Rocker Arm and Shaft: 0.015–0.040 mm
• Contact Surface Width at Valve End: 12 mm
• Adjusting Screw Specification: M9×1
• Unit Weight: Approx. 1.2 kg per piece

4. Functions & Features

• Precise Power Transmission: Optimized rocker ratio ensures accurate valve timing and stable valve lift.
• Long Service Life: Combination of alloy cast iron and copper bushing delivers great resistance to alternating loads and wear.
• Adjustable Clearance: Equipped with M9 adjusting screw and lock nut for precise control of valve lash.
• High Temperature Stability: Resists thermal deformation and carbon deposition, free from sticking during long-term operation of gas engines.
• Reliable Lubrication: Built-in oil passage provides forced lubrication for bushings and contact surfaces to reduce wear.

5. Replacement & Compatibility

• Genuine Alternative Part No.: 12420479 (No updated replacement part)
• Recommended Aftermarket Brands: ELRING, INA, CTP. The rocker ratio, shaft diameter, material and adjusting screw specification must be fully matched.

6. Installation Instructions

1. Inspection & Cleaning: Check the rocker arm for cracks and deformation, and confirm the bushing is firmly fitted. Ensure all oil passages are unobstructed.
2. Fitting Clearance: Maintain the clearance between rocker arm and shaft within 0.015–0.040 mm. Replace the bushing if the tolerance is out of range.
3. Installation Sequence: Install the rocker shaft first, then fit the rocker arm and mount the adjusting screw.
4. Valve Lash (Cold State): 0.25–0.30 mm for intake valves; 0.35–0.40 mm for exhaust valves.
5. Tightening Torque: Lock nut of adjusting screw: 20±5 Nm; Rocker shaft bolt: 40±5 Nm.
6. Complete Replacement: Replace together with valves, valve seat inserts, valve guides, valve stem seals and valve springs to ensure reliable performance of the entire valve train.