Application Simple transmission chain drive
Failure mode Rubbing wear on the face of the side plates, the end of the side plates and the pin end.
Diagnosis The chain has been rubbing against some fixed point on the circuit. From the wear pattern it seems likely that the chain has worn a groove in the fixture, probably initiated by the harder pin ends.
Solution Realign the chain drive before the damage to the chain becomes too serious and the chain has to be scrapped.