How does a manual transmission work?
With a manual transmission, the driver selects gears by pushing in the clutch pedal
, thus decoupling engine and gear set, and then manually moving a shift lever
, which engages a linkage that controls the movement of the gears along the input shaft
. Moving the lever forward or rearward selects between the two gears available on a given linkage; cars with four gears, or speeds, use two linkages; cars with five or six speeds use three linkages. The driver manually changes between linkages by moving the shift lever left and right.
When the pedal is depressed, the clutch cable
pulls on the clutch linkage to disengage the clutch, and decouples the engine and the gear set so that the transmission can be safely shifted. The clutch cable is the steel braided cable found on manual transmission vehicles that connects the clutch pedal mechanism to the transmission clutch linkage. When the clutch cable begins to have problems, it can cause issues with shifting the vehicle, which will take away from its overall drivability. Usually a problematic clutch cable will display a few symptoms that can alert the driver that a problem has occurred and needs to be serviced: transmission slips out of gear, the pedal exhibits a hard clutch, or the clutch pedal sinks to the floor. What is the difference between automatic and manual transmissions?
One of the primary differences between an automatic transmission
and a manual transmission
is that automatics don't use a clutch (typically, anyway). Instead, the automatic transmission relies on a torque converter
to decouple the engine and the gear set.
The torque converter functions on principles of fluid dynamics, whose basic premise is simple: when the engine is spinning slowly, very little torque is transmitted through the fluid and turbine inside the torque converter; when the engine is spinning quickly, almost all the engine's torque is transmitted to the transmission. The torque converter is why automatic transmission cars "creep" forward when idling and in "drive", as a small amount of the engine's torque is being supplied to the transmission's input shaft.
It isn’t easy to isolate and diagnose a torque converter issue without taking the transmission/drivetrain apart, but there are several symptoms to look for. A few of the signs of a malfunctioning torque converter include: shuddering, contaminated fluid, gears change at high RPMs and strange sounds such as clicking or whirring, slipping, overheating, or shuddering.
Finally, another important part of the transmission, the clutch flywheel
, is, simply put, a mechanical device that can store rotational energy. It also helps reduce the vibration and keeps the gears working when the clutch is used. Thus, it is a very important part of the car, especially in manual transmission engines, and just like any other machine part, there will be times when the flywheel stops working properly. So, what are the signs that your engine's flywheel is damaged? Gear slippage, burnt smell, or clutch vibrations.