How do you drive a non-synchromesh gearbox?

Answer 1

The technique for driving a vehicle fitted a non-sychromesh is to match the engine speed to the transmission speed by raising or lowering the engine speed.

The technique to change up is this:

1. Depress clutch (not all the way to the floor, just enough to disengage)
2. Move gearstick into neutral position
3. Release clutch
4. Depress the clutch once the engine has slowed the appropriate amount
5. Move the gearstick into the higher gear.

The number of revolutions per minute to reduce depends on the normal gap between the gears (usually 600 to 800 rpm), whether the vehicle is speeding up or slowing down

The technique to downshift is

1. Depress cluch
2. Move gearstick into neutral position
3. Release clutch
4. Increase the engine speed by the appropriate amount
5. Depress clutch
6. Move gearstick into the lower gear

Again, the amount to increase depends on the transmission and vehicle acceleration.

There is no real substitute for practice.

If the speeds are not matched, the gears cannot engage, no matter how hard the gearstick is pushed.

If the gear does not engage, then the engine speed needs to be adjusted. Generally a high pitched grind indicates the engine is too fast, and a lower pitched grind indicates the engine is too slow.

If the gear cannot be engaged, the vehicle needs to be stopped as it is very dangerous to let a vehicle coast in neutral while the driver is hunting for a gear.