Manual Transmission Bearings
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: Ball bearings consist of small steel balls, separated from each other by a steel cage. They're capable of withstanding both radial and axial loads. Ball bearings provide for the smooth operation of high-speed components like axle shafts.
Roller Bearings: Roller bearings have more surface area than ball bearings. These bearings are well suited for heavy applications. Tapered roller bearings are used in differentials, final drives, and transfer shafts and 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 held in a round cylinder by assembly grease. Handle with care; needle bearings are 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.
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. The 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 selective washers and a dial gauge placed against the end of a shaft or gear to adjust end play.
Never use white, chassis, or bearing grease when installing bearings and washers in a transmission. These greases do not mix well with and may contaminate the manual transmission fluid.