(1) When dismantling various assemblies and parts, check whether there are original assembly marks on coupling parts, rotating parts and non-interchangeable parts before dismantling, and re-mark if there are no such parts (such as tires and Mark the installation position of the rim) to prevent the original fit or balance state from being damaged due to wrong installation. As the saying goes: Repairman, how to disassemble, how to install, not afraid of missing parts for a long time, but afraid of forgetting how to install.
(2) If there is a requirement for the installation direction, the original direction should be checked or marked to prevent reverse installation. Such as pistons, cylinder gaskets, connecting rods, etc., marking is very important.