This week we are carrying out a Root Cause Analysis (RCA) into a failed Caterpillar 3412 engine and it’s a great example of the damage that can be caused by a lack of proper lubrication (if you can use the word “great” to talk about damage!)
The heat at the big end was so excessive that the bearing shell distorted, damaging the crank pin in the process, and evidence of the temperatures is shown in the bluing of the connecting rod.
We’re still carrying out the investigation into the cause, but this is going to require a major overhaul including replacing the crankshaft.
Possible causes of the damage include:
• Blockage in oil ways caused by debris not picked up by the filter
• Incorrect oil used
• Maintenance routine not followed, or wrong maintenance schedule in place
• Faulty bearing
• Oil dilution by fuel
• Ovality of the big end
You’ll see from the list above that regular and proper maintenance could well have prevented a failure, which just hammers home the importance of not ignoring maintenance – it might “cost” you in the short term, but that cost is an investment if it keeps your engine running!