Grinding of Crank Pin of Daihatsu Engine

About Grinding of Crank Pin of Daihatsu Engine

We were approached by a ship management company based in Athens, Greece having ninety vessels regarding breakdown of the crankshaft of Daihatsu Engine 5DK-20.

The engine & crankshaft details are given below:

S. NO	Crankshaft Details
1	Engine Make	Daihatsu
2	Engine Model	5DK-20
3	Crankpin Diameter Standard	170 mm
4	Crankpin Bearing Width	78 mm
5	Place of Execution of Job	Navlakhi Port (INDIA)

RA Power Solutions team of two technicians with portable crankshaft repair equipment was immediately deputed to Navlakhi Port in western part of India. On inspection of crankshaft following was observed:

Main observations of the crankshaft of Daihatsu Engine 5DK-20 after inspection:

i) The crankpin no. 3 was badly damaged due to seizure of the bearing. The bearing white metal was badly embedded on the crankpin diameter.

ii) On visual inspection it was observed that the radius fillet of both sides was damaged and original profile of radius fillet was lost.

iii) After removal of bearing material from the crankpin diameter deep scoring marks and multiple depressions were observed.

vi)The crankpin was subject to MPI test for crack detection, multiple cracks were observed having length ranging from 3.0 mm to 19 mm. All the cracks were hairline cracks.

v) Hardness was taken and was found on the higher side even up to 515 BHN. This was the scattered hardness.

vi) Deflection of complete crankshaft was checked and was observed within limits.

Rejection of crankshaft by reputed Singapore based crankshaft repair companies

The damaged crankshaft of Daihatsu 5DK-20 was inspected by three leading crankshaft repair companies based in Singapore who rejected the crankshaft and declared it beyond repair on site because of following reasons:

i) The crank pin of Daihatsu 5DK-20 diameter is 170mm and the bearing width is only 78 mm. The companies in Singapore don't have the equipment which can be placed on the crank pin with small bearing width for on site grinding purpose.

ii) Since both sides of the radius fillet were damaged they insisted on removal of the crankshaft from the engine block and sending it to the workshop for repair if possible.

iii) The presence of multiple cracks and higher hardness of crankpin was also one of the reasons for rejection of the crankshaft.

Successful repair executed by RA Power of Daihatsu engine 5DK-20 crankshaft with damaged radius fillet

RA Power Solutions technicians successfully repaired the radius fillet of both sides and executed the grinding of crank pin no.3 to the under size of 2.0 mm.

All the parameters were checked after crankshaft repair as per the International standard and manufacturer manual and were observed within limits.

RA Power Solutions is the International leader in repair of crankshaft up to 700 mm diameter. We are the only company in the world which manufacture & supply on site crankshaft repair equipment.

For your requirement of repairing the crankshaft, crankshaft with damaged radius fillet on the vessel or anywhere in the world please contact us.

Precision Grinding for Daihatsu Marine Diesel Engines

Our service specializes in high-precision grinding of crank pins for Daihatsu marine diesel engines. We utilize advanced portable onsite grinding machines operated by skilled technicians, ensuring minimal downtime. Each process achieves strict tolerances as low as 0.015 mm and improves crank pin hardness up to 62 HRC. Engine reliability and fuel efficiency are enhanced, complying with global quality standards for marine applications.


Comprehensive Inspection and Documentation

Every grinding operation comes with detailed post-job inspection reports, dimensional certificates, and hardness test reports. Our quality assurance includes non-destructive testing (NDT), ensuring the repaired crank pin meets exacting standards. Clients receive clear documentation for compliance and maintenance records, offering full transparency and peace of mind after each job.