Abrasive wear is yet another issue, frequently due to particulate make any difference suspended within the oil. This can be why Used Oil Investigation for dress in metals and contaminants is important to observe gearbox well being. Will have to not be Utilized in autos with a wet clutch/friction drives: https://martinbgggf.blogdanica.com/34104654/the-smart-trick-of-gearbox-oil-treatment-that-no-one-is-discussing