*Lubrication
Check for proper lubrication.
Lubricants on chain and sprockets and all reservoirs. If not properly lubricated, the joints will have a rusty color and the pins of the connecting link when removed will be discolored brown. Properly lubricated chains will be bright and shiny.
*elongation
Lubrication failure
Excessive overloads or shocks
Displacement of bearings
Displacement or failure of take-ups.