Crankshafts

The crankshaft is one of the most important components of any engine, responsible for converting the motion of the pistons into rotary motion that powers the vehicle's wheels. Its precision craftsmanship and durability directly impact the engine's performance and longevity. At Global Parts, you'll find a wide selection of used car parts. , including crankshafts fitted to BMW , Audi , Mercedes , Volkswagen , Mini and others. Crankshafts used in brands such as BMW, Audi, and Mercedes vary in design depending on the engine generation, journal diameter, and number of cylinders. For example, the BMW N57 crankshaft The crankshaft used in 3.0d engines weighs approximately 22-24 kg and features a specific crank geometry adapted to high torque exceeding 560 Nm. The M54B30 crankshaft, on the other hand, is a lighter design, designed for the naturally aspirated 3.0 in-line 6 engine, with operating torque of around 300 Nm. These differences ensure the crankshaft is optimally matched to the engine's characteristics, and its compatibility with accessories (pulley, bearings, position sensor) is crucial for the engine's proper operation.

What is a crankshaft and what is its importance?

The crankshaft is an engine component that performs many key functions:

• Energy Conversion – Converts the linear motion of the pistons into rotary motion, which is transmitted to the drive system.
• Distributing forces – The crankshaft balances the forces generated during engine operation, ensuring smooth operation.
• Accessory Drive – Through its connection to belts and pulleys, the crankshaft drives other systems such as the alternator and water pump. The precise manufacture of the crankshaft and its proper lubrication are crucial for reliable engine operation. Crankshafts can be forged or cast. Forged shafts, used in more powerful BMW engines (e.g., the N57S), are characterized by greater torsional stiffness and higher maximum combustion pressure. Cast shafts (popular, for example, in 1.6–2.0 VAG engines) are lighter and less expensive, making them ideal for engines with lower dynamic loads. In practice, both types ensure proper engine operation, provided they are properly matched to the specific model's design.

How to choose the correct crankshaft for your vehicle?

The crankshaft selection process can be broken down into four simple steps:

1. Identification of the drive unit – the most important thing is the engine code, e.g. N57D30A, M54B30, or OM651 in Mercedes.
2. Analysis of technical parameters – crank arm length, main journal diameter, number of crank throws.
3. Hardware compatibility – fit for dual-mass flywheel, sealing rings and sensors.
4. Verification of assembly fit – shafts vary depending on the year, power version and gearbox (e.g. ZF automatic vs manual). This makes the selection precise and allows for the installation of the appropriate model, e.g. the BMW E46 crankshaft, which was available in several engine versions with different journal diameters.

Why is it worth taking care of the crankshaft?

The crankshaft is constantly exposed to high mechanical and thermal loads, making regular inspection and maintenance essential. Neglecting this component can lead to:

• Engine damage due to excessive friction or overheating.
• Uneven engine operation, loss of power and increased fuel consumption.
• Serious failures that may require costly replacement of the entire drive system. At Global Parts we offer original used crankshafts , which have undergone detailed quality tests, ensuring their full functionality. Modern crankshafts operate at speeds reaching up to 6,000–7,000 rpm in inline-6 engines and over 4,000 rpm in diesel engines. The main journal surfaces are induction hardened, achieving a hardness of up to 55–60 HRC, ensuring years of service. Proper lubrication is maintained by an oil film just 0.02–0.05 mm thick, which protects against friction and maintains shaft stability.

How to choose the right crankshaft?

When choosing a crankshaft, there are several key factors to consider:

• Vehicle-specific fit – Every engine has unique design requirements. At Global Parts, you'll find crankshafts designed for BMW , Audi , Mercedes , Volkswagen , Mini , and more.
• Technical condition – A used crankshaft should be free from cracks, signs of wear and deformation.
• Service history – It is important that the shaft comes from a vehicle with a known service history to ensure its durability.

Parameters and compatibility table

Below are some examples of differences between popular crankshafts used in BMW:

Engine model	Example shaft mass	Material	Type	Model Compatibility
M54B30	approx. 20–21 kg	Cast steel	cast	BMW E46, E39, E60 (3.0 R6)
N57 3.0d	22–24 kg	Forged steel	forged	BMW F10, E70, F01 (3.0d)
N57S (M550d)	approx. 25 kg	Reinforced forged steel	forged	Special M Performance versions

Why choose used crankshafts?

Used car parts, such as crankshafts, are an excellent solution combining cost-effectiveness with high quality. By choosing used crankshafts, you gain:

• Lower costs – Used components are much cheaper than new ones, but offer equally high quality.
• Ecology – Recycling car parts helps reduce the amount of automotive waste.
• A wide range – In our store you will find crankshafts for the most popular car brands. Used crankshafts, such as those offered at Global Parts, are sourced from fully functioning engines and inspected for straightness, journal tolerances, and compatibility with standard or oversized bearings. These crankshafts can have micron-scale wear variations—standard tolerances are typically 0.01–0.03 mm, which is still within the factory operating parameters of many engines. This makes them a fully functional and cost-effective solution.

How to take care of the crankshaft?

To ensure that your crankshaft continues to function reliably for years to come, it is important to follow a few rules:

• Change your engine oil and filters regularly to ensure proper lubrication.
• Check the condition of the crankshaft bearings to prevent excessive wear and vibration.
• Check the tension of the drive belts, which may affect the operation of the shaft. If you need to replace your crankshaft, you'll find the right used car parts at Global Parts. that will restore your vehicle to full working order. The durability of the crankshaft is also influenced by the proper fit of other system components : the oil pump, lubrication channels, and main bearings. Some engines, such as the BMW N57, feature a variable displacement oil pump that adjusts pressure to load. In the M54 engines, the proper functioning of the oil separator is crucial, maintaining stable lubrication at high RPMs. This ensures the crankshaft operates in optimal conditions.

FAQ - Frequently asked questions about crankshafts

Question	Answer
What is the purpose of the crankshaft in a car engine?	The crankshaft is the engine component responsible for converting the reciprocating motion of the pistons into rotary motion transmitted to the gearbox and drive system.
How does a crankshaft work in practice?	When the engine is running, the pistons press against the crankshaft, which begins to rotate, generating torque that allows the vehicle to be propelled.
What does crankshaft-engine compatibility mean?	This is the matching of its parameters – journal diameter, number of crank throws, weight, material – to a specific engine code, e.g. N57, M54B30, B47.
Does the BMW E46 crankshaft fit other models?	It may be compatible with several engine versions (e.g. M54), but it always depends on their design parameters.
What are the symptoms of a malfunctioning crankshaft?	Typically, these include vibrations, noise resulting from bearing play, and loss of power at high RPM.
Are N57 crankshafts different from M54B30?	Yes - the N57 is a forged shaft, heavier and adapted to the high torque of a diesel engine; the M54B30 is a lighter shaft, designed for the R6 petrol engine.
How to choose a crankshaft for a specific car?	The easiest way is by engine code or VIN number - this allows you to clearly determine the design parameters.

Summary: Crankshafts at Global Parts Automotive Store

Crankshafts are a fundamental element of every engine, affecting its performance, durability, and reliability. By maintaining their technical condition, you ensure trouble-free operation of your vehicle for years to come. The Global Parts automotive store invites you to browse our extensive selection of genuine used car parts . Whether you're looking for car parts for BMW , Audi , Volkswagen , Mercedes, Mini , and more, you'll find them at competitive prices. We strive to ensure every customer finds the right parts for their car, and if you have any questions or concerns about selecting the right components, we're happy to help! Please contact us – we're here to help! For more information and interesting facts, visit our automotive blog .