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Five 5 speed Transmission

How a transmission works and what is its purpose

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First lets cover how a manual transmission works and what is its purpose. Every engine has something called a redline - a numerical rpm value at which the engine cannot go past. Engines need gears to be able to have low speed torque through gear multipliers, yet still be able to shift those gears for higher end top speed without going over their max rev limit. Without a transmission the engine would be slow to start with just high gears, or fast to start, but have a very limited top speed.

5 speed transmission cut away diagram


Some essential parts of any transmission are the clutch, gears, and shifter. The purpose of a clutch is so that you can temporarily disconnect the engine and the transmission so that the engine can run even if the car is standing still. When you release the pedal, the clutch releases and connects the transmission directly to the engine.

The shaft that the clutch's connects to is called the layshaft. The layshaft and its gears are connected as one piece, so that they move in unison. The clutch's shaft and the layshaft are connected directly, so that if the clutch's shift is spinning, so is the layshaft. The layshaft receives power directly from the engine whenever the clutch is connected this way.

There is a third and final shaft located just above the layshaft that connects directly to the wheels, so that if the wheels are spinning, the third shaft is spinning. The gears connected to the last shaft turn independently of the last shaft, and are connected to the layshaft, so that if the car is coasting, yet the engine is turned off, then the gears on the last shaft do not turn, yet the shaft itself does. The yellow shaft has a gear-like object between the gears called the collar. The collar is directly connected with the last shaft, so it always spins with the last shaft. The purpose of the collar is to connect the gears to the last shaft with grooves on the side called dog teeth, which fit into each other, therefore connecting the last shaft with its gears. While the collar is not connected to any of the gears, the car is in neutral. The collar is attached to a gear selector fork, which is connected to the shifter.

The reverse gear is slightly different from all of the other gears. It has a small gear between the layshaft and itself called the idler gear, which makes it so the gear attached to the final shaft turns in the opposite direction of all of the other gears, therefore making it impossible to shift into reverse while the car is in motion. On the next page is a picture of a 5-speed transmission and all of its parts (the Blue gears are the gears connected to the last shaft. The yellow shaft is the last shaft. The red gears and red shaft are the layshaft, the green shaft and gear is the shaft connected to the clutch. The purple gears are the collars, and the gear selector fork is connected to the collars. The idler gear is between Reverse and the layshaft.)


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