BMW E46 E60 E87 E90 E91 Diesel M47N M47N2 Engine Crankshaft Crank Shaft 7793904

BMW E46 E60 E87 E90 E91 Diesel M47N M47N2 Engine Crankshaft Crank Shaft is a crankshaft assembly component designed for BMW diesel engines from the M47N and M47N2 families. Thanks to its factory geometry and precise balancing, it ensures stable operation of the power unit, reducing torsional vibrations and loads on the main bearings. This is a solution for users who expect consistency with the factory engine design and predictable operating parameters.

Specifications and technical data

• SKU: 7807188
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7793904
• Substitutable numbers: 11217807188, 11217793958, 11217793634, 11217787985, 11217793635, 11217787984, 11217793959, 7807188, 7793958, 7793634, 17787985, 7793635, 7787984, 7793959, 7793904
• Fuel type: Diesel
• Category: Crankshafts

Purpose and compatibility with BMW diesel engines

The presented crankshaft belongs to the Crankshafts category and is dedicated to BMW diesel engines from the M47N and M47N2 families used in, among others, the 3, 5, and 1 series models. The crankshaft design is optimized for the operating characteristics of diesel units, which generate high torque at relatively low engine speeds.

A properly selected diameter of the main and connecting rod journals, as well as the correct shape of the webs and oil channels, allows for the maintenance of a stable lubricating film, which is crucial for engine durability. The use of the original crankshaft geometry facilitates the maintenance of proper bearing clearance and correct cooperation with connecting rods and the flywheel.

Technical characteristics and role in the crank-piston system

The crankshaft in the M47N/M47N2 engine is responsible for converting the reciprocating motion of the pistons into rotational motion transmitted to the gearbox and drivetrain. BMW diesel units require a component with appropriate stiffness and fatigue resistance, which is why the following are key:

• stable guidance of the main journals in the engine block,
• properly shaped counterweights to reduce vibrations,
• oil channels ensuring even lubrication of the connecting rod journals.

A well-chosen crankshaft reduces the risk of micro-cracks, excessive wear of the bearings, and unwanted vibrations, which translates into more uniform operation of the power unit and stable oil pressure parameters.

Benefits of using an original BMW crankshaft

Using a crankshaft from the same design family as the engine allows for maintaining factory assembly tolerances and operating characteristics. In practice, this means:

• easier fitment to the existing block and connecting rods without the need for modifications,
• preservation of the load distribution in the crank-piston system as intended by the manufacturer,
• consistency with factory service procedures and technical documentation.

For workshops and users, this means a more predictable assembly process and the ability to precisely control parameters after engine regeneration or overhaul. Choosing an OEM component also facilitates subsequent diagnostics, as the engine behaves in accordance with the manufacturer's specifications.

Condition, verification, and use in repairs

The offered crankshaft is a used component, which makes it an attractive cost-effective alternative for overhauling BMW diesel engines. This type of component is particularly useful for:

• overhauling M47N/M47N2 units after bearing seizure or damage,
• restoring the factory engine configuration after a mechanical failure,
• building an engine using original components instead of replacements of unknown origin.

Before installation, standard workshop procedures are recommended: checking radial runout, measuring journal diameters, assessing working surfaces, and verifying for any potential micro-cracks. This allows for the selection of appropriate bearings and the maintenance of the clearances required by the manufacturer, which is crucial for long-term and stable engine operation.

Expansion of the BMW crank and drive system

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other elements from the same group, such as additional shafts, components cooperating with the crank system, or parts related to the drivetrain, check the available parts in the BMW Crankshafts category.

When working on the drive axle or differential, it is worth taking care of the entire drivetrain. Practical tips on assessing the condition of used components can be found in the guide Second-hand differential – what you need to know about used differentials, sensors, and drive systems, which helps in making informed decisions when selecting components for the drivetrain.