When driving a car with a manual transmission, it is imperative to first depress the clutch pedal before up-shifting or down-shifting gears. Once this pedal is depressed to the floor, the clutch disengages, thereby disconnecting the engine from the transmission. At this moment, the driver can shift up or down the gears. But do you know you can shift gears in manual transmission without having to use the clutch pedal?
Typically, you have to depress the clutch pedal to disengage the clutch. Shifting gears while the clutch is engaged isn't advisable as this could damage the gears, especially their teeth. Disengaging the clutch essentially cut off the power supply from the engine. Since the shifting process doesn’t have to work again power and torque, the gears won’t get damaged. Once you take your foot off from the clutch pedal, the clutch engages once again to connect the engine to the transmission.
However, it is possible to shift gears up or down without having to depress the clutch pedal. This means that you are shifting gears while the clutch is still engaged, and the engine is still connected to the transmission. Being able to shift gears without using the pedal could mean a lot when you are driving and the clutch seemed to have failed.
The technique of shifting gears without depressing the clutch pedal is called as slip-shifting. It is also called as float shifting and dead sticking.
To do this, you need a very good timing and a working tachometer for reference. When shifting gears up, you can try to slip-shift when the engine speed is between 3,000 rpm and 3,500 rpm. The desired engine speed for slip-shifting to a higher gear, however, varies from one vehicle to another. In this engine speed, the two gears (lower and higher gears) match their rotational speeds, allowing you to upshift without damaging the gears.
Upon reaching the desired engine speed, you should take your foot off the gas pedal and then pull the shifter out of the lower gear and press it to the higher gear in sequence. Once the engine and the gearbox have the same speed, the shifter will slide into gear. After this happen, you need to depress the gas pedal to speed up.
When slip-shifting to a lower gear, you can try to do so at engine speeds of between 1,200 rpm and 1,500 rpm. First, you have release some pressure on the accelerator to slow down the car. Then, burp the car by depress the gas pedal for a second and release it to ease pressure on the gearbox. When you reach the desired engine speed, pull the shifter out of the higher gear. At this moment, the transmission is in neutral.
Now, you should depress the gas pedal until the engine speed reaches 3,000 rpm. Then press the shifter to the next lower gear and hold. Next, you need to slowly bring down the engine speed. Once it matches the transmission speed in the desire gear, the shifter will slide into it.
To note, slip-shifting is only possibly if the car in on the move. Likewise, it is impossible to engage the first gear from a full stop without using the clutch pedal.