A Leading Company based in Singapore approached RA Power Solutions regarding the failure of the crankshaft of a Daihatsu 6DKM-36. The vessel was at the port of Johor Bahru, Malaysia. RA Power Solutions deputed two technicians along with an onsite crankshaft grinding machine to undertake the repair of the crankshaft of the Daihatsu 6DKM-36 on board the vessel at Johor Bahru, Malaysia.
The major crankshaft details of the Daihatsu 6DKM-36 are as follows:
| S. No. | Crankpin Details | |
| 1 | Engine Make | Daihatsu |
| 2 | Engine Model | 6DKM-36 |
| 3 | Crankpin Diameter Standard | 325.00 MM |
| 4 | Crankpin Bearing Width | 135.00 MM |
| 5 | Grinding of Crankpin Number | #03 |
| 6 | Place of Execution of Grinding of Crankpin | Johor Bahru, Malaysia |
| 7 | Name of Shipping Company | Reputed Company from Singapore |
| 8 | Date Of Execution | 27.04.2026 to 04.05.2026 |
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| Damaged Crankpin of Daihatsu 6DKM-36 Engine | Crankpin Wear and Scoring Marks on Crankshaft of Daihatsu 6DKM-36 Engine |
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| MPI Testing on Crankpin of Daihatsu 6DKM-36 Engine | Non-Destructive MPI Testing of Crankpin – Daihatsu 6DKM-36 Engine |
Observation of The Crankshaft of Daihatsu 6DKM-36
i) On visual inspection, it was noted that the bearing of crankpin number 03 was damaged, and bearing material was accumulated in the sump.
ii) On opening the connecting rod, the bearing was found to be badly damaged. Crankpin number 03 was also embedded with bearing material.
iii) The bearing material was removed, and crankpin number 03 was inspected for dimensions (taper & ovality).
The following minimum and maximum dimensions were noted:
| SIZE OF CR PINS BEFORE REPAIR | |||||||||
| A | Aa | C | Cc | B | Bb | Min | STD | Ovality | |
| CR-1 | |||||||||
| CR-2 | |||||||||
| CR-3 | 324.96 | 324.81 | 324.98 | 324.85 | 324.93 | 324.78 | 324.78 | 325.00 | 0.22 MM |
| CR-4 | |||||||||
| CR-5 | |||||||||
| CR-6 | |||||||||
iv) Due to high temperature and rubbing of the bearing on the crankpin, multiple scoring marks were observed.
Action Taken by RA Power Solutions for the Successful Repair of Daihatsu 6DKM-36 Crankshaft
The grinding of crankpin number 03 was started with an onsite crankshaft grinding machine. Initially, considering the ovality, it was estimated that the crankpin was to be undersized by 0.5 mm. However, on evaluation, it was decided to reduce the diameter of the crankpin further by 0.5 mm. The undersize of 1.00 mm was maintained.
The readings observed after grinding are pasted below:-
| SIZE OF CR PINS AFTER REPAIR | |||||||||
| A | Aa | C | Cc | B | Bb | Min | STD | Ovality | |
| CR-1 | |||||||||
| CR-2 | |||||||||
| CR-3 | 324.01 | 324.01 | 323.99 | 323.99 | 324.00 | 324.00 | 323.99 | 324.01 | 0.02 MM |
| CR-4 | |||||||||
| CR-5 | |||||||||
| CR-6 | |||||||||
The ovality was maintained within 0.02 mm.
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| Smooth Crankpin Finish After Grinding and Polishing – Daihatsu 6DKM-36 | Crankshaft Grinding and Repair of Daihatsu 6DKM-36 Engine |
RA Power Solutions has been extending crankshaft repair services all over the world for 46 years of experience. We have successfully repaired and saved ten thousand (10000) crankshafts from rejection by using our experience. A few crankshafts have been repaired by us under deviation with the presence of cracks or undersizing beyond the last limit prescribed by the manufacturer.
For all repairs, including the above crankshaft of Daihatsu 6DKM-36, we provide records of the inspection report before and after the repair of the crankshaft. These reports are signed and stamped by the Chief Engineer of the vessel. On request, we can share these reports with our clients.
This case once again demonstrates RA Power Solutions’ capability to undertake critical crankshaft repairs worldwide with high accuracy, technical expertise, and proven field experience.
For more information on onsite crankshaft repair, grinding of crankshaft, and crankshaft polishing, please email us at rajshahani@rapowersolutions.com, or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.
