During the inspection of the Detroit 16V92 engine, our engineers found something that could cause catastrophic failure had the engine been left to run…
As you’ll see from these pictures, there’s been a weld repair on several parts of the crankshaft, and one is incredibly close to the filet on the pin.
This is one place you should never attempt any type of weld.
The heating of the components causes stress fractures within the material.
You can just see from the slight white powdery coating that it has been crack detected in the past, but these fractures would not be on the surface and therefore not visible, even with MPI detection.
There is also no evidence that it has been re-balanced.
Had this engine been signed off to run based on a satisfactory detection report, the fractures could have increased leading to catastrophic engine failure.
So: how can you repair damage to a crankshaft?
The only safe way to repair a crankshaft is if the damage is contained within the pins – you can grind them to undersize.
Any other damage would, unfortunately, mean a new crankshaft is required. Bad news, but much better than the risk of blowing the whole engine.