Mercedes W204 M274 Starter Motor Ring Gear Automatic Gearbox A2740300012

The Mercedes W204 M274 Starter Ring Gear for Automatic Transmission is a precision component from the Flywheels and Gears group, designed for the starting system in Mercedes vehicles with a gasoline engine and automatic transmission. It is responsible for the effective transfer of torque from the starter to the drivetrain, ensuring a stable and repeatable engine start. This solution is dedicated to users who expect proven, original geometry and correct cooperation with factory equipment.

Specifications and technical data

• SKU: A2740300012
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2740300012
• Substitutable numbers: A2740300012, A 274 030 00 12
• Fuel type: Petrol
• Gearbox type: Automatic
• Category: Flywheels & Flexplates

Purpose and Function in the Starting System

Starter ring gears in Mercedes W204 series vehicles with the M274 engine work directly with the starter and flywheel, forming a crucial element of the power transfer path during starting. The appropriately selected tooth profile and their arrangement allow for smooth engagement with the starter drive gear, limiting the risk of slippage, noise, and excessive wear. For gasoline engines with automatic transmissions, the correct selection of the ring gear is particularly important for the smooth operation of the entire drivetrain.

Drivetrain Compatibility

The presented starter ring gear for Mercedes W204 with M274 engine is designed to work with gasoline engines and automatic transmissions. This means maintaining appropriate stiffness, balance, and matching the starting torque characteristic of this drive configuration. Using the correct ring gear minimizes shock loads on the starter and flywheel, which translates to a longer lifespan for these components.

By maintaining the factory tooth geometry and working diameter, this element allows for:

• stable engagement with the starter drive gear,
• reduction of the risk of mechanical damage during frequent starts,
• maintenance of correct cooperation with the automatic transmission during engine start-up.

Characteristics of the Used Component

The offered ring gear is from the used parts group, allowing for an economical repair of the starting system while maintaining the original manufacturer's specifications. This type of component is particularly useful in situations where the teeth on the flywheel's circumference have been damaged or characteristic grinding noises occur during engine start-up. Replacing the ring gear with a correctly selected element from the same construction group restores proper engagement and eliminates undesirable operational symptoms.

The choice of a used, original starter ring gear is often preferred by mechanics and Mercedes enthusiasts because it allows for compliance with factory manufacturing tolerances and starting system operating parameters.

Application in Service and Modifications

Starter ring gears in vehicles with gasoline engines and automatic transmissions are replaced both as part of standard repairs and during more advanced service work, such as gearbox removal or drivetrain modernization. For projects focused on improving throttle response or increasing power, a stable and efficient starting system remains an essential element of the entire configuration.

If you are interested in a broader context of using used components in modernization projects, it is worth reading the article describing a practical approach to tuning using second-hand parts: Best Used Parts for Tuning Your Car. You will find tips on how to consciously select components to maintain a balance between cost and durability.

Expanding Repair Scope within the Same Group

If you are planning a comprehensive repair or modernization of the engine and drivetrain area in your Mercedes and need other elements from the same group, such as additional gears, components cooperating with the flywheel, or torque transfer components, check the available parts in the Mercedes Flywheels and Gears category.