Is There a Clutch In an Automatic Transmission?

Is There a Clutch In an Automatic Transmission?

Last Updated August 4, 2019 | Sam Padgett

If you drive an automatic car, you probably have been baffled at this elusive clutch that manual drivers rattle on about. The clutch really does draw the line between automatic and manual vehicles; it's tied to that sneaky third pedal, anyhow. Since the clutch is critically important for manual vehicles you might wonder “Is there a clutch in my automatic vehicle?” This question may be even more pertinent if you engage in performance driving. Does your automatic Mustang have a clutch? Rest assured, this isn’t some sort of impossible zen question like, “What is the sound of one hand clapping?”; there is a clear answer.

Automatic Transmission

Does an Automatic Transmission Have a Clutch?

Yes, there is a clutch in your automatic transmission, but it’s not exactly like a clutch in a manual vehicle. The term clutch isn’t exclusive to the part in manual transmissions; it more or less refers to a specific mechanical device, along with axles and gears.

What is a clutch then? A clutch, in general terms, is a series of friction plates that can effectively adhere one surface to another. Using ceramic materials engineered to have a high coefficient of friction, the clutch is meant to temporarily glue parts together, effectively transferring the mechanical energy from one to another.

The Clutch

Clutch Pad

In a manual gearbox, the clutch is meant to transfer power from the flywheel of the engine to the transmission. In order to prevent excessive loads on the engine, which would cause a stall, the clutch can be engaged and disengaged in order to keep the load on the engine steady while cycling through gears.

What about an automatic vehicle then? There are no engine differences between manual and automatic cars, so both styles of vehicles have to deal with the same constraints. In order to deal with the same problems that the clutch solves in a manual gearbox, automatic vehicles are equipped with something called a torque converter.

There are some forms of clutches in automatic vehicles, however. Instead of the one clutch controlled by a clutch pedal, there is a series of clutch plates inside of the automatic transmission that is applied automatically. In order to understand this, however, some of the principles of an automatic transmission need to be explained first.

Torque Converter

In a manual gearbox, each of the gears is determined by standard single gears that are locked into place individually. In an automatic transmission, however, there are planetary gears. These are a series of gears that are aligned in between a center gear and a surrounding ring gear. Basically, this alignment allows for several different gear ratios to be expressed from the same alignment without having to move. Additionally, automatic transmissions have several of these planetary gear sets lined up in a row. The clutches, or more correctly, clutch packs, are the driving force of the gear changes in the automatic transmission. Between the different gear sets, there are clutch packs that, when activated, combine the different gear sets together, thus changing the overall gear ratio. So, there is a clutch, or rather clutches, inside of an automatic transmission, but they are purely for joining gears together.

What’s a Dual-Clutch Transmission?

Duacl Clutch Transmission

There is another way an automatic can have a clutch. It can even have two. The dual-clutch transmission (DCT) is an effective combination of the best parts of both a manual and an automatic gearbox. Unlike a manual, a DCT controls when the car shifts gears, and unlike an automatic, there’s no torque converter. In the place of the torque converter is a series of two clutches, each of which is applied to separate gear shafts. One gear shaft contains odd number gears, while the other contains even gears. While all of the gear shifts are performed by internal computers, drivers still retain the ability to freely select which gear to drive in. The way this transmission shifts gears is by preselecting the following gear on the shaft that is not currently in use and switching out the active clutch to execute the gear shift. This means that there is no loss of engine power due to slippage from a torque converter, nor is there a risk of stalling the engine or seriously damaging any of the important internal components (clutch, synchros, etc.) due to driver error. Additionally, dual-clutch transmissions don’t have power dips upon gear shifts because the automated gear shifting is quick and precise.

A Mustang with A DCT?

In the upcoming future, there very well could be two clutches in your automatic Mustang. The 2020 Shelby Mustang GT 500 is rumored to come equipped with a 7-speed DCT. This is exciting news for Mustang enthusiasts of all kinds since it will have the power of a manual, and the clean and continuous gear shifting of an automatic.

2019 Shelby GT500

To reiterate, there is a series of clutch packs in the standard automatic transmission of a Mustang, but they are different from the clutch you would find on a manual. At the end of the day, the same principles are being applied to move both vehicles, so naturally, some of the same parts would appear in both, as well. It doesn’t matter which type of Mustang you drive either because, at CJ Pony Parts, we have what you need to enjoy your vehicle to its fullest.

Is There a Clutch In an Automatic Transmission?

The question of “Does my automatic Mustang have a clutch?” may keep you up at night. Since the clutch is an integral part of a manual transmission, how does an automatic transmission compensate? As it turns out, there are clutches in your automatic Mustang, but they aren’t exactly like their manual counterparts.