Bearings are what enable the gears to rotate easily. They are typically made away from bronze or brass, and they in shape into races (or grooves) within the gearbox housing. Hard shifting, lowered gasoline efficiency, and burning smells are only a lot of the indicators of a nasty transmission filter. https://filtergearbox51582.webbuzzfeed.com/34590845/filter-gearbox-fundamentals-explained