change gear
1. Literally, to switch a car, bicycle, or other vehicle into a different gear. You need to change gear if you're going get the car up that steep hill.
2. To move or switch from one thing (such as a task or topic) to another, often quickly. Once our proposal gets approved, we can change gear and focus on the next phase of the project.
change gear
begin to move or act differently, usually more rapidly. This expression derives from literally engaging a different gear of a motor vehicle in order to alter its speed. Compare with in gear (with a gear engaged, and so ready for action) and its opposite out of gear . To move up a gear means literally ‘change to a higher gear’; the phrase is often used figuratively to mean ‘put more effort into an activity’.