We carry out onsite crankshaft grinding for main and auxiliary marine engines as well as land-based diesel generating sets without removing the crankshaft from the engine. In our experience, this approach is often the most practical solution when vessel schedules, cargo operations, or plant shutdowns leave little time for workshop repairs. By performing crankshaft grinding in situ, we reduce downtime and eliminate the risks associated with dismantling, transportation, and reinstallation.
Onsite Crankshaft Grinding Repair
Our present capacity for onsite crankpin grinding is up to 700 mm diameter, covering most marine diesel engines and industrial generating sets. Before any machining begins, we inspect the crankshaft for scoring, taper, ovality, runout, bearing damage, and journal wear. These measurements help us determine whether the crankshaft can be restored within the OEM regrind limits and the specified undersize bearing shell requirements.
The portable crankshaft grinding equipment we use is designed specifically for onboard and onsite applications. Once the machine is mounted on the crankshaft, it provides stable grinding conditions while minimizing vibration. This allows us to maintain the required journal geometry, fillet radius, and Ra surface finish throughout the grinding process. Depending on vessel operating conditions and the owner's approval, we can also carry out crankshaft grinding while the vessel is sailing, avoiding unnecessary delays until the next port or drydock.
Every crankshaft grinding job is monitored using precision measuring instruments. During machining, we continuously check journal diameter, taper, ovality, alignment, and surface finish to ensure compliance with the engine manufacturer's tolerances.
From our experience, the condition of the crankpin and main journal directly affects bearing performance and engine reliability. Even small changes in taper, ovality, or surface finish can break the hydrodynamic lubrication film and speed up bearing wear. We verify every critical measurement before, during, and after machining to ensure the crankshaft operates within OEM tolerances. Once grinding and polishing are complete, final readings are documented so the engine can be returned to service with confidence.
We also undertake crankshaft grinding for small-diameter crankpins with limited bearing width. These repairs demand careful machine alignment and continuous dimensional verification throughout the grinding process. Once machining is complete, the journal is polished to the specified Ra surface finish, and all critical dimensions are checked before the engine is returned to service.
