Bearings are what allow the gears to rotate smoothly. They are typically produced from bronze or brass, and so they match into races (or grooves) inside the gearbox housing. On the other hand, inside filters are costlier than externals and it is far tougher to interchange interior filters, when you’ll https://angeloseowc.blogacep.com/39353647/little-known-facts-about-filter-gearbox