Mercedes A209 M112 Crankshaft Gear Pulley Sprocket A1550500003

Mercedes A209 M112 Crankshaft Gear Pulley Sprocket is a precision timing system component designed for diesel engines, engineered for stable power transmission and maintaining the correct synchronization of the powertrain. Thanks to its design compliant with manufacturer standards, it provides a solid foundation for professional repair or regeneration of the timing system in Mercedes vehicles. This is a solution for users who expect a technically matched component and want to maintain the efficiency of their diesel engine at the proper level.

Specifications and technical data

• SKU: A1550500003
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1550500003
• Substitutable numbers: A1550500003, A 155 050 00 03
• Fuel type: Diesel
• Category: Tensioners & Pulleys

Purpose and role in the timing system

The crankshaft gear pulley sprocket is responsible for transferring torque from the crankshaft to the other timing components, ensuring proper valve timing and stable operation of the diesel engine. A correctly selected gear sprocket minimizes the risk of timing chain/belt skipping, uneven engine operation, and cold-start issues.

In diesel engines, where mechanical loads are significantly higher than in gasoline units, proper tooth geometry and fitment to the crankshaft are crucial for the durability of the entire system. Using a component that complies with factory specifications allows for maintaining engine refinement and reducing vibrations transmitted to the auxiliary equipment.

Construction and fitment for diesel engines

The presented gear sprocket has been designed to work with diesel units, which means it is adapted to the characteristic torsional loads and the specific operation of the timing system in diesel engines. A properly selected tooth profile and distribution contribute to:

• stable power transmission across the entire RPM range,
• reduction of mechanical noise in the timing zone,
• limiting the wear of cooperating elements, such as the timing chain or belt.

By maintaining factory mounting parameters, the gear sprocket can be used as a replacement part during standard service procedures without the need to modify other components.

Category Tensioners and pulleys – service application

Although the crankshaft gear sprocket is a different type of element than classic tensioners or pulleys, in service practice, it is often replaced at the same stage of work during comprehensive timing system maintenance. Replacing the gear sprocket in parallel with tensioners and pulleys allows you to:

• reduce the risk of having to re-intervene in the timing system in the near future,
• achieve a consistent level of wear across all cooperating elements,
• increase the predictability of service intervals.

This approach is particularly important in cars with diesel engines, where access to the timing system can be time-consuming and labor costs constitute a significant part of the total repair cost.

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other elements from the same group, such as tensioners, guide pulleys, or components cooperating with the belt or chain, check the available parts in the Mercedes Tensioners and pulleys category.

Used condition and practical assembly aspects

The offered element comes from the used parts group, which in service practice often represents a reasonable compromise between repair cost and maintaining the manufacturer's original specifications. In the case of crankshaft gear sprockets, it is crucial to verify the condition of the working surfaces of the teeth and mounting seats to ensure proper seating on the shaft and cooperation with other timing components.

Before installation, a standard service procedure is recommended, including checking clearances, assessing the wear of cooperating elements, and setting timing marks in accordance with the technical documentation of the given engine. This approach allows you to utilize the potential of a used part while maintaining operational safety.

Substantive support and powertrain operation

When planning repairs within the powertrain, it is also worth paying attention to the condition of the engine accessories, including the charging system. Symptoms such as flickering warning lights, voltage drops, or starting problems can result from both improper timing operation and alternator wear. Practical tips on selecting and replacing charging system components can be found in the article When is it worth replacing an alternator with a used one: a practical guide for drivers, which helps assess the cost-effectiveness of using components from the secondary market.