Manual transmissions contain different types of bearings. Each type has a unique purpose and application. Due to their design; tapered roller bearings are used at the ends of the transmission shafts. There’;'s a preload applied, check with the vehicle manufacturer for specifications.
: Ball bearings are capable of withstanding both radial and axial loads. They consist of small steel balls that are kept separated from each other by a steel cage. They ride in a channel of the hardened steel race. These bearings are used for high-speed applications like axle shafts.
: Roller bearings have more surface area than ball bearings. These bearings are well suited for heavy applications. Tapered roller bearings are usually used in differentials, final drives, and transfer shafts. Tapered roller bearings require a slight preload. Always check with the vehicle manufacturer’s specifications before setting preload on a tapered roller bearing.
Needle Bearings: Needle bearings consist of small needle-like bearings. These small bearings are often held in a round cylinder by assembly grease. It's important to be careful when handling needle bearings, because they’re not fastened to the cylinder, and can fall from the carrier. Use petroleum jelly or Vaseline to replace and hold any bearings that have fallen out. Never use white, chassis, or bearing grease when installing bearings or washers in a transmission. These greases do not mix well with and may contaminate the manual transmission fluid.
Torrington Bearings: A different design of needle bearing called a Torrington bearing contains small needle bearings in a cage. They are also known as caged needle bearings. These bearings are placed in a spoke pattern like a bicycle wheel inside of a thrust washer. They reduce friction while controlling shaft end play.
Thrust Washers: Thrust washers adjust and control shaft end play. Use a dial gauge placed against the end of the shaft or gear and selective washers to adjust end play.
Original article from: https://www.freeasestudyguides.com/manual-transmission-bearings.html