Float shifting or floating gears, also called "slip shifting", "dead sticking", or "bang shifting", is the process of changing gears, in typically a non-synchronous transmission, without depressing the

clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

. Shifting in this manner is also used with synchronous

manual transmission A manual transmission (MT), also known as manual gearbox, standard transmission (in Canadian English, Canada, British English, the United Kingdom and American English, the United States), or stick shift (in the United States), is a multi-speed ...

s, particularly after a clutch failure, to prevent destroying the

synchromesh A manual transmission (MT), also known as manual gearbox, standard transmission (in Canada, the United Kingdom and the United States), or stick shift (in the United States), is a multi-speed motor vehicle transmission system where gear changes ...

es with the power of the engine. Drivers can shift non-synchronous transmissions without using the clutch by bringing the engine to exactly the right RPM in neutral before attempting to complete a shift. If done improperly, it can damage or destroy a transmission. Some

truck driver A truck driver (commonly referred to as a trucker, teamster or driver in the United States and Canada; a truckie in Australia and New Zealand; an HGV driver in the United Kingdom, Ireland and the European Union, a lorry driver, or driver in ...

s use this technique with the higher gears. The technique is sometimes also used on

motorcycle A motorcycle (motorbike, bike; uni (if one-wheeled); trike (if three-wheeled); quad (if four-wheeled)) is a lightweight private 1-to-2 passenger personal motor vehicle Steering, steered by a Motorcycle handlebar, handlebar from a saddle-style ...

s, but has largely been replaced by quickshifters for competitive use.

Technique

After bringing the engine up to speed in a gear, the driver senses the need to upshift. To get out of the current gear without using the clutch, the driver backs off slightly on the accelerator and gently pulls the

gear stick A gear stick (rarely spelled ''gearstick''), gear lever (both UK English), gearshift or shifter (both U.S. English), more formally known as a transmission lever, is a metal lever attached to the transmission of an automobile. The term ''gear s ...

toward the neutral position. If they back off enough, a moment comes when the engine is neither driving the car nor being driven by the car; at that moment the stick moves freely, and the transmission "effortlessly" shifts out of gear. Next, to get into the chosen higher gear without using the clutch, they back off on the accelerator a little more and gently push the gear stick toward the chosen higher gear. A moment comes when the engine

RPM Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or r⋅min−1) is a unit of rotational speed (or rotational frequency) for rotating machines. One revolution per minute is equivalent to hertz. Standards ISO 80000-3:2019 def ...

s has decreased enough to synchronize that chosen gear; at that moment, the transmission "effortlessly" shifts into that gear. To shift down, the driver similarly backs off on the accelerator and "falls out of" the current gear, but then pushes a little harder on the accelerator to ''increase'' the RPMs enough to match and allow them to "fall into" the chosen ''lower'' gear.

Pros and cons

Float shifting can reduce clutch wear because it is used so much less (only for starting from a standstill). Conversely, improper engagement of a gear (when the engine and transmission speeds aren't matched) can cause wear on the synchros and lockouts, and damage the gears by physically grinding them together due to a difference in speed.

References

Driving techniques {{Truck-stub