Bearings are what allow the gears to rotate easily. They are typically designed outside of bronze or brass, and so they fit into races (or grooves) while in the gearbox housing. Nonetheless, interior filters are dearer than externals and it is far more challenging to switch interior filters, when you’ll https://filtergearbox86308.dailyhitblog.com/39512944/how-much-you-need-to-expect-you-ll-pay-for-a-good-filter-gearbox