Bearings are what allow the gears to rotate smoothly. They are generally manufactured from bronze or brass, they usually in good shape into races (or grooves) from the gearbox housing. Even so, interior filters are dearer than externals and it is much more challenging to interchange inner filters, when you’ll https://filter-gearbox31851.elbloglibre.com/34072170/not-known-facts-about-filter-gearbox