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ROCKER ARM

ROCKER ARM Valve Train Components for Demanding Diesel and Gas Engines

Valve train components are the mechanical link between the camshaft and the combustion chamber, converting rotary motion into precise valve lift and timing. This category includes the ROCKER ARM, cam followers, hydraulic lash adjusters, pushrods, valve bridges, guides, springs, retainers, and associated shafts and bearings. In heavy-duty diesel and gas engines—whether propulsion units on a vessel or stationary power generation—the valve train defines how efficiently air enters and exhaust exits the cylinders, directly influencing output, fuel consumption, emissions, and service life. For purchasers and technical teams, choosing robust valve train components is a strategic decision that protects uptime and total cost of ownership.

Technical function: valve train components and ROCKER ARM in diesel engine and marine engine applications

The valve train controls intake and exhaust events with micrometer accuracy, cycle after cycle. The cam profile sets lift and duration; followers and tappets transfer that motion; the ROCKER ARM pivots it to the valve stem; springs stabilize the system and close the valves; guides and seats maintain alignment and sealing. In a diesel engine with high peak firing pressures, the ROCKER ARM must withstand enormous contact loads while keeping friction and wear under control. In a marine engine operating under variable load and continuous duty, consistent geometry and surface finish across all valve train components ensure smooth operation, low noise, and predictable maintenance intervals.

Modern ROCKER ARM OEM parts often integrate needle bearings or precision bushings at the pivot to minimize friction, plus hardened pads or rollers at the valve contact to resist pitting and scuffing. Materials range from forged alloy steels to surface-treated components (carburized, nitrided, or DLC-coated contact zones) that stabilize hardness and reduce micro-welding under boundary lubrication. Hydraulic lash adjusters within the assembly can compensate for thermal growth, maintaining valve lash within a tight window, safeguarding timing and valve seating during cold starts and hot running.

By keeping valve lift true to the cam profile, the valve train governs volumetric efficiency, turbocharger response, and cylinder scavenging. Stable dynamics at high rpm prevent valve float, protect against piston-to-valve contact, and maintain precise emissions control. A correctly engineered ROCKER ARM for marine engine duty also reduces parasitic losses, improving brake-specific fuel consumption and extending component life in challenging salt-laden environments.

  • · Precise timing and lift for clean combustion
  • · High load capacity under continuous-duty cycles
  • · Optimized friction via bearings, coatings, and finishes
  • · Stable valve lash and alignment across temperature ranges
  • · Durable materials and heat treatment against wear
  • · Compatibility with OEM parts interfaces and tolerances

Importance for engine operation: why valve train components matter

Reliability starts at the top end. Worn or misaligned valve train components create a cascade of issues: lash drift that alters timing, accelerated cam lobe and follower wear, rocker pad pitting, valve guide ovality, and spring fatigue. The immediate effects include hard starting, misfire under load, poor turbo spool, increased smoke, and rising exhaust temperatures. Over time, blow-by escalates and oil becomes contaminated with metallic debris, threatening bearings and turbocharger integrity.

Critical failures can be catastrophic. A seized ROCKER ARM or collapsed adjuster can lead to a dropped valve, valve-to-piston contact, or broken pushrods, resulting in major downtime and costly overhauls. Maintaining a robust valve train preserves compression, ensures clean combustion, and stabilizes emissions—key for meeting class and port requirements in a marine engine while protecting fuel economy and component longevity.

Advantages of OEM spare parts suitable for valve train components

Specifying OEM spare parts suitable for valve train components secures the exact geometry, metallurgy, and surface treatments the engine was engineered to run with. Tight tolerances in a ROCKER ARM, follower radius, or lash adjuster bleed rate are not “nice-to-have”; they are essential to keep the system in dynamic balance across the full operating envelope.

  • · Performance: Maintains designed valve lift, duration, and dynamics.
  • · Reliability: Consistent heat treatment and coatings resist scuffing and spalling.
  • · Budget: Lower lifecycle cost through longer service intervals and reduced collateral damage.
  • · Service life: Proven fatigue strength for continuous-duty diesel and gas engines.
  • · Fit and compatibility: Correct interfaces for shafts, pins, lash adjusters, and bridges.
  • · Predictable maintenance: Known wear patterns that align with engine manuals.

When sourcing ROCKER ARM OEM parts, purchasers gain confidence that contact geometry, hardness gradients, and bearing selections match the engine’s load spectrum—especially vital in high-BMEP diesel applications and marine engine environments where salt, vibration, and long run hours stress every component.

MOPA as your partner for OEM spare parts valve train components

MOPA is an experienced and reliable partner for OEM spare parts for valve train components. We support purchasers, shipowners, and technical managers with fast sourcing of ROCKER ARM assemblies, followers, bridges, adjusters, springs, and related hardware for diesel and gas engines. Our focus is speed, quality, and security in the trade of OEM parts—backed by transparent documentation, precise identification by engine model and serial, and logistics tailored to dock schedules and overhaul windows.

From single ROCKER ARM replacements to full top-end kits, MOPA streamlines the process: accurate part cross-referencing, prompt quotations, and shipment handling that minimizes laytime. You receive components that align with OEM specifications, helping your maintenance team return the engine to service swiftly and with confidence.

Conclusion

Valve train components—especially the ROCKER ARM—are central to power, efficiency, and the operational safety of diesel and gas engines. Specifying OEM spare parts suitable for valve train components preserves timing accuracy, reduces wear, and protects budgets through stable, long service intervals. With MOPA as your partner, sourcing the right parts becomes faster, safer, and fully aligned with the technical demands of marine and industrial operations.

Filter products

ROCKER ARM - 02021860 suitable for MWM & Deutz engines
ROCKER ARM - 02021860 suitable for MWM & Deutz engines

Precision in Engine Performance: Rocker Arm in FocusDiscover our product, the Rocker Arm (comparative number: 02021860), which is available as an OEM replacement part. This component is suitable for MWM & Deutz engines and plays a crucial role in the category of Valve Train Components. In demanding marine and stationary applications, the Rocker Arm provides the necessary reliability.Robust Design for the Highest DemandsWeighing 7 kg, our Rocker Arm combines stability and efficiency. As an OEM replacement part, it offers an optimal solution for engines designed for MWM & Deutz. The use of durable materials ensures that the Rocker Arm is well suited for various operating conditions.

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ROCKER ARM - 12171801 suitable for MWM & Deutz engines
ROCKER ARM - 12171801 suitable for MWM & Deutz engines

ROCKER ARM with the comparison number 12171801 suitable for MWM & Deutz engines

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ROCKER ARM - 12851405 suitable for Deutz engines
ROCKER ARM - 12851405 suitable for Deutz engines

High-performance Rocker Arm with Comparison Number 12851405The Rocker Arm with the comparison number 12851405 represents an excellent solution for professionals requiring optimal performance. This OEM spare part is distinguished by its high quality, meeting the specific demands of Deutz engines. The Rocker Arm ensures efficient control of the valve train components and offers long-lasting functionality.Optimal Functionality for Deutz EnginesOur Rocker Arm is suitable for motorized equipment powered by Deutz. Weighing only 0.121 kg, this OEM spare part provides an ideal combination of lightness and strength, perfect for use in marine and stationary applications. Experience how your engines evolve with this component.

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Sale price: €171.11 Regular price:€190.13(10% saved)
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ROCKER ARM - 4720500233 suitable for MTU engines
ROCKER ARM - 4720500233 suitable for MTU engines

Rocker arm for Your Engine NeedsDiscover our product, the rocker arm with the comparison number 4720500233, an essential component for your requirements. This OEM replacement part is specialized and ensures long-term performance in engines that are in demand for marine and stationary use.

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Sale price: €110.48 Regular price:€122.76(10% saved)
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ROCKER ARM - 21460261 suitable for Volvo/Volvo Penta engines
ROCKER ARM - 21460261 suitable for Volvo/Volvo Penta engines

ROCKER ARM with the comparison number 21460261 suitable for Volvo/Volvo Penta engines

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Sale price: €498.24 Regular price:€553.61(10% saved)
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ROCKER ARM - 04503741 suitable for Deutz engines
ROCKER ARM - 04503741 suitable for Deutz engines

Premium Rocker Arm for High-Performance ApplicationsExperience our top product, the rocker arm with the reference number 04503741. This replacement part is a crucial element for the valve train and has been carefully designed to meet the demands of various applications. Weighing only 0.124 kg, our rocker arm provides the necessary force transmission essential for the optimal operation of your engines.

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Sale price: €50.02 Regular price:€55.58(10% saved)
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ROCKER ARM - X52605500066 suitable for MTU engines
ROCKER ARM - X52605500066 suitable for MTU engines

ROCKER ARM with the comparison number X52605500066 suitable for MTU engines

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Sale price: €519.55 Regular price:€577.28(10% saved)
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ROCKER ARM - 9060500434 suitable for MTU engines
ROCKER ARM - 9060500434 suitable for MTU engines

Rocker Arm for Efficient Engine PerformanceDiscover our rocker arm, an essential product in the category of valve train components. This OEM replacement part is specially designed to provide optimal functionality for high-performance engines and fits perfectly for MTU engines.Replacement Parts with Reference NumberWith the reference number 9060500434, you can be assured of acquiring a reliable component. Our rocker arm ensures that your engines operate smoothly and have a long service life. Choose our OEM replacement part for the best durability.

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Sale price: €73.76 Regular price:€81.95(10% saved)
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ROCKER ARM - 51042016243 suitable for MAN D-engines
ROCKER ARM - 51042016243 suitable for MAN D-engines

Quality That ConvinceDiscover our rocker arm OEM replacement part, the comparison number 51042016243. This product is suitable for MAN D engines and ensures the highest precision in the valve train.

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Sale price: €57.49 Regular price:€63.88(10% saved)
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ROCKER ARM - 5500500333 suitable for MTU engines
ROCKER ARM - 5500500333 suitable for MTU engines

Reliable Rocker Arm with Comparison Number 5500500333Discover our rocker arm with the comparison number 5500500333, the excellent product for successful engine applications. This rocker arm component, categorized under valve train components, offers a very good fit and performance. It is specifically designed for the 331 series of MTU engines and suitable for the engine types 12V331TC81 and 12V331TC92. Weighing 1.168 kg and with compact dimensions of 13.3 x 13.3 x 6.4 cm, this replacement part proves to be a robust solution for your engine needs.

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Sale price: €1,894.98 Regular price:€2,105.53(10% saved)
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ROCKER ARM - 51042015064 suitable for MAN D-engines
ROCKER ARM - 51042015064 suitable for MAN D-engines

Quality Features of the Rocker ArmDiscover our Rocker Arm OEM replacement part with the comparison number 51042015064, suitable for MAN D engines. This product is part of the efficient Valve train components specifically designed for use in diesel and gas engines.Internal Quality AssuranceThe product quality of our OEM replacement parts is ensured through strict internal controls. With the comparison number 51042015064, we offer you a product that delivers precise performance for your engines.

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Sale price: €131.41 Regular price:€146.02(10% saved)
ROCKER ARM - 12166359 suitable for MWM & Deutz engines
ROCKER ARM - 12166359 suitable for MWM & Deutz engines

### Product Description: Rocker Arm (Comparison Number: 12166359)Excellent Performance with Rocker Arm Discover the rocker arm with comparison number 12166359, which has been specifically optimized for the valve train. This OEM spare part offers reliable performance and efficiency. The quality of the materials and the precise workmanship ensure that this rocker arm functions optimally even under load.Compatible with MWM & Deutz Engines Our rocker arm is compatible with MWM & Deutz engines and contributes to the precise operation in engine performance. These development standards enable outstanding service life and bearing tolerance, allowing the product to perform well even in challenging applications.

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ROCKER ARM - 51042016083 suitable for MAN D-engines
ROCKER ARM - 51042016083 suitable for MAN D-engines

Measured Product Description: Rocker Arm 51042016083Discover the Rocker Arm with the comparison number 51042016083, an essential OEM spare part that unleashes reliability and performance. This item belongs to the valve train components and is suitable for MAN D engines. The Rocker Arm is crucial for the precise control of the valves and sustainably improves engine performance.Reliable Quality for Engine ApplicationsWeighing just 0.243 kg, this product offers the perfect combination of lightness and stability. OEM spare parts like the Rocker Arm are suitable for MAN D and are important for ensuring smooth integration into your existing engines while maintaining the rated performance.

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ROCKER ARM - 12164730 suitable for MWM & Deutz engines
ROCKER ARM - 12164730 suitable for MWM & Deutz engines

Rocker arm: Comparison number 12164730 for MWM & Deutz enginesDiscover the rocker arm with the comparison number 12164730, a product specifically designed for electric motors. This OEM replacement part offers superior quality and reliability to maximize the performance and efficiency of your engine.Robust construction for optimal functionalityThe rocker arm, weighing 0.118 kg, allows for easy handling and installation. This replacement part, compatible with MWM & Deutz engines, ensures an exact fit and a high level of durability. Rely on a product that effortlessly withstands the demands of marine and stationary applications.

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ROCKER ARM - 5900530340 suitable for MTU engines
ROCKER ARM - 5900530340 suitable for MTU engines

Efficient Performance with the Rocker ArmOptimize the performance of your engines with our rocker arm, which carries the reference number 5900530340. This OEM spare part is the perfect product to ensure the functionality of the valve train components. With its perfect fit and thoughtful design, our rocker arm meets the highest quality standards and ensures a long service life.Suitable for MTU EnginesThis precisely developed product is suitable for MTU engines and meets the specific requirements necessary for smooth operations and maximum efficiency. By using OEM spare parts, such as our rocker arm, you ensure the powerful functionality of your systems.

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Sale price: €2,476.71 Regular price:€2,751.91(10% saved)
ROCKER ARM - 03373557 suitable for MWM & Deutz engines
ROCKER ARM - 03373557 suitable for MWM & Deutz engines

Rocker arm with comparison number 03373557Discover the reliable product with the comparison number 03373557 – a rocker arm specifically optimized for the requirements of MWM & Deutz engines. Weighing only 0.27 kg, this OEM replacement part offers the best solution for your valve train components. The materials designed for high performance ensure durability and efficiency in demanding applications.

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ROCKER ARM - 21953320 suitable for Volvo/Volvo Penta engines
ROCKER ARM - 21953320 suitable for Volvo/Volvo Penta engines

OEM Replacement Part with Comparison Number 21953320The rocker arm with the comparison number 21953320 is a top-quality OEM replacement part optimized for use in engines. Weighing 0.58 kg and featuring precise dimensions, this product meets important requirements and is manufactured according to the standards in the article group valve train components.Efficient Performance for Compatible Volvo/Volvo Penta EnginesThis rocker arm product is suitable for Volvo/Volvo Penta engines and plays a crucial role in the functionality of the valve train. The use of this replacement part enhances the efficiency and longevity of your engines. Rely on the quality that our experienced team ensures when selecting this OEM replacement part.

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ROCKER ARM - 3520501033 suitable for Mercedes engines
ROCKER ARM - 3520501033 suitable for Mercedes engines

Precise Rocker Arm Replacement PartDiscover our rocker arm product, which is excellently suited to your needs. With the comparison number 3520501033, this OEM replacement part ensures outstanding performance in your engines. Rely on parts designed for high demands.Optimal Solution for EnginesOur rocker arm offers excellent precision and is specifically designed for Mercedes engines. This OEM replacement part provides long life and optimal functionality through careful manufacturing and high quality standards.

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ROCKER ARM - 51042016159 suitable for MAN D engines
ROCKER ARM - 51042016159 suitable for MAN D engines

ROCKER ARM with the comparison number 51042016159 suitable for MAN D engines

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ROCKER ARM - 51042015022 suitable for MAN D-engines
ROCKER ARM - 51042015022 suitable for MAN D-engines

Superior Performance: Rocker Arm (Reference Number 51042015022)The rocker arm is an essential product known as an OEM replacement part. This replacement part (Reference Number 51042015022) ensures optimal functionality in demanding engines. Thanks to its high-quality manufacturing, the rocker arm is perfectly suited for applications in maritime, stationary, and railway sectors. This product is indispensable for smooth operation of your engines.

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ROCKER ARM - 03373569 suitable for MWM & Deutz engines
ROCKER ARM - 03373569 suitable for MWM & Deutz engines

ROCKER ARM with the comparison number 03373569 suitable for MWM & Deutz engines

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ROCKER ARM - 3853158 suitable for Volvo/Volvo Penta engines
ROCKER ARM - 3853158 suitable for Volvo/Volvo Penta engines

Rocker arm compatible with Volvo/Volvo Penta enginesExperience the rocker arm with the part number 3853158, specially designed to meet versatile requirements for engines. This product is compatible with Volvo/Volvo Penta engines, making it an essential replacement part for technical projects. The precise fit ensures that the rocker arm can be seamlessly integrated into your engines.Reliability through OEM replacement partsThe rocker arm, which belongs to the category of valve train components, impresses with its high quality. This OEM replacement part has been manufactured without compromise to meet the demands of manufacturers and optimally support your engines. Users of Volvo/Volvo Penta engines will appreciate the durability and reliability of this replacement part.

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Sale price: €71.91 Regular price:€79.90(10% saved)
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ROCKER ARM - 9060500933 suitable for MTU engines
ROCKER ARM - 9060500933 suitable for MTU engines

Quality Products for Valve Train and MoreDiscover the OEM replacement part, the rocker arm, with the comparison number 9060500933. This quality part is ideally suited for use in valve train components. With its high precision, the rocker arm ensures optimal functionality when used in various engines.

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Sale price: €115.26 Regular price:€128.06(10% saved)
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ROCKER ARM - 360106450226 suitable for MWM & Deutz engines
ROCKER ARM - 360106450226 suitable for MWM & Deutz engines

Rocker Arm for Efficient EnginesDiscover the rocker arm with the comparison number 360106450226, an essential OEM spare part that provides balanced performance for your machines. This valve train component is specifically designed to optimize the functionality of your engines. Our rocker arm weighs 0.476 kg and is a benchmark for efficiency and robustness.Suitable for MWM & Deutz EnginesWith the comparison number 360106450226, our product is directly compatible with MWM & Deutz engines. This rocker arm has been tailored to the specific needs of these manufacturers, offering excellent precision. Benefit from components that deliver top performance in your machine.

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Sale price: €304.20 Regular price:€338.00(10% saved)