Mercedes G Class Diesel Conversion Kit

The Overland-G Diesel Engine Conversion Kit defines the drivetrain architecture for Mercedes G-Class builds developed beyond factory limitations. It is not a single component, but a complete system designed to integrate modern inline Mercedes diesel engines into expedition-ready platforms.

This conversion is typically based on OM612, OM613 or OM648 engines — selected for their mechanical robustness, torque characteristics and long-distance reliability. The goal is not only to replace the engine, but to redefine how the vehicle performs across extended travel, load conditions and remote environments.

Each conversion begins with a refurbished Mercedes diesel engine prepared specifically for drivetrain integration projects. Because no two builds are identical, the engine is delivered as part of a configured system rather than as a standalone unit. Specification is determined based on the vehicle, intended use and overall build direction.

For builds that require increased output and durability, the system can be configured with a dedicated performance package. This includes an upgraded turbocharger, reinforced valve train components and recalibrated engine management software tailored to the conversion.

To integrate the inline diesel engine into the G-Class chassis, the system includes dedicated engine mounting brackets engineered specifically for OM612, OM613 and OM648 installations. These mounts ensure correct positioning, load distribution and structural compatibility within the vehicle.

Because these conversions operate outside of the original factory electronics architecture, the system also includes a standalone electrical integration solution. This allows the engine to operate independently within custom drivetrain builds and provides a clean foundation for further system integration.

Thermal management is a critical element of any diesel conversion. The Overland-G heavy duty cooling package provides a complete cooling architecture designed for the G-Class engine bay. Depending on configuration, the system can include engine radiator, air conditioning condenser, water-to-air aftercooler, transmission oil cooler, power steering cooler and an 800W high output fan with standalone PWM control. The assembly is built around a modular layout with removable diffuser and support for custom temperature sensor integration.

Due to space limitations in the G-Class engine bay, water-to-air intercooling is often the most effective solution. The system includes multiple configurations, including solutions integrated into the original intake manifold or custom intake systems with integrated cooling elements.

For vehicles equipped with snorkel intake systems, a sealed aluminum airbox solution is available. Designed for W463 applications using OM613 or OM648 engines, the airbox connects to the snorkel through a dedicated intake interface and uses a K&N filter element, optimized for off-road and expedition environments.

The system can also be configured with a 3-inch performance exhaust using V-band connections. Depending on requirements, this can include catalytic converters, Cerakote coating or heat shielding for thermal management and durability.

All components are developed to function as a unified drivetrain system. This is not a universal kit — it is a configurable platform designed around the specific vehicle and build objective.

Before ordering, we recommend contacting us with your exact Mercedes G-Class model, year and configuration so the correct engine, cooling, electronics and supporting components can be specified.

Included components

• Refurbished OM612 / OM648 Diesel Engine
• Performance Package
• Engine Mounting Kit
• Conversion Electronics Kit
• Heavy Duty Cooling Package
• Water-to-Air Intercooler Kit
• Aluminum Airbox
• Performance Exhaust System

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