How does a manual transmission collar engage a gear?

A manual transmission collar engages a gear primarily through a mechanism known as dog teeth. Dog teeth are projections that fit into corresponding recesses on the gears, allowing them to lock together securely when the collar moves into position. This engagement creates a solid connection between the collar and the gear, enabling the transmission to transmit power from the engine to the drivetrain effectively.

The collar itself slides along the input shaft and is moved by the driver's action via the gear shift lever. Once the driver selects a gear, the collar shifts and aligns the dog teeth with the gear's recesses, engaging the gear without the need for any hydraulic systems or excessive force. This mechanical connection allows for smooth engagement of the gear, which is crucial for the performance and efficiency of the vehicle's transmission system.

Other options, such as hydraulic pressure or rotating gears, deal with different mechanisms not involved in the direct engagement of gears through a collar in manual transmissions. While a lever is used by the driver to shift gears, it is not the method by which the collar actually engages the gear itself. Hence, the use of dog teeth is the correct and specific method for engagement in this context.