The crankshaft bearing lets the shaft turn freely in the crankcase of the Good Luck chainsaw. It works at high revs and under load, so it is one of the first parts to wear out.
Signs of wear: play in the shaft, humming and vibration at revs, oil leaks at the oil seals. It is best to replace the bearings together with the oil seals, and to clean the crankcase thoroughly before assembly.
Before buying, check your saw model: for Chinese saws and their analogues, parts of different generations may differ, so rely on the marking and comparison with the old part.
