In a manual transmission, how does the collar engage a gear?

In a manual transmission, the collar engages a gear using a mechanism known as dog teeth. This system consists of protruding "teeth" on the gears and matching slots on the collar. When the driver moves the gear shifter, the collar aligns with the desired gear, and the teeth interlock with corresponding slots, securing the connection between the collar and the gear. This direct mechanical engagement allows for efficient power transfer from the engine to the drivetrain, enabling the vehicle to change speeds effectively.

The use of dog teeth is critical because it provides a strong and reliable engagement that is essential for the performance and durability of the transmission during shifting. Other mechanisms, such as hydraulics, magnets, or belts, are not typically involved in the direct gear engagement in manual transmissions, which distinguishes the dog teeth method as the appropriate choice for this question.