MAN marine crankshafts
The crankshaft carries every combustion event in the engine through to the propeller shaft. We supply genuine MAN crankshafts for D-Series marine diesels, new and reconditioned, matched to your exact engine and rating.
Crankshafts
Genuine MAN crankshafts with the engines they fit. Reconditioned units are available for some references, so confirm the exact crankshaft against the model and serial number on your engine’s data plate.
| Part no. | Description | Engine / application | Availability |
|---|---|---|---|
| 51.02100-6019 | Crankshaft |
| In stock |
| 51.02101-6126 | Engine crankshaft |
| In stock |
| 51.02101-6121 | Engine crankshaft |
| In stock |
| 51.02101-6124 | Engine crankshaft |
| In stock |
| 51.02101-0801 | Engine crankshaft |
| In stock |
| 51.02101-0764 | Engine crankshaft |
| In stock |
| 51.02100-6179 | Engine crankshaft |
| In stock |
Click a part number for full specifications and to request a quote. All crankshafts listed are genuine MAN, in stock and dispatched same day. Not sure which you need? Send us your engine model and serial number and we will confirm the correct crankshaft before anything ships.
Crankshafts: symptoms, causes and sensible replacement
The crankshaft is the backbone of the engine. It turns the up-and-down force of the pistons into the rotation that drives the boat, carrying every combustion event through its main and big-end journals and out to the gearbox. It is forged, machined and balanced to fine tolerances, and when a journal or a bearing lets go the damage rarely stays in one place.
The warning signs are usually felt before they are seen: a deep knock that rises with load, falling oil pressure, more vibration than usual, or bright metal in the oil and filter. A spun bearing, a scored journal, or crankshaft end-float outside limits all point the same way, and the bottom end needs attention before the engine is run again.
Almost every crankshaft failure traces back to lubrication: oil starvation, contaminated oil, a blocked gallery, or a failed oil pump, with overload, over-fuelling and coolant in the oil doing the rest. By the time a crank is damaged the bearings, and often the block itself, need inspecting too. Depending on the reference, a crankshaft can be replaced new or supplied as a reconditioned unit ground to standard undersizes, a lower-cost route back to service where the core is sound.
Our recommendations for crankshaft work:
- Replace the main and big-end bearing shells as a set, and measure journals and clearances against the MAN figures
- Inspect the block, caps and oil galleries before fitting. A crank fails for a reason, and that reason is often still in the engine
- Establish and fix the root cause, oil supply, filtration or cooling, so the new crank is not the next casualty
- Ask about reconditioned options where available, often a sound and lower-cost choice
- Renew the front and rear oil seals, and prime the oil system before the first start
We supply genuine MAN crankshafts, new and reconditioned, with a 2-year warranty and worldwide dispatch. Send us your engine model and serial number, or a photo of the data plate, and we will confirm the correct crankshaft and the options open to you before anything is ordered.