AT Transmission question

I just saw a local ad for a transmission shop that claims a transmission has about 2000 moving parts? I am not very mechanically includes (but I did install my TT ultimate lol).

That made me think, I don't have a clue how exactly a transmission (MT/AT) works. Never had any interest to find out until now.

Any pointers? (I can google, but I'm asking for some GOOD info lol)

 

Check out a site called "How stuff works".It's pretty detailed explanations with pictures,etc.

 

x2, that's a pretty open ended question. That how stuff works thing will at least give you the basics, then you can post back more specific questions if you have any. Not trying to be an ass, but there are a lot of moving parts so a full out response on how a transmission works would take a while.

 

Yeah, I guess y'all have a point. I'll be back (I'm sure)

 

M/T:

In the bellhousing: Consists of the flywheel, clutch and pressure plate. Without getting extremely technical, when the m/t is "in gear" all 3 components basically become 1 large rotating unit. When you press in the clutch, you disengage the pressure plate as you shift into another gear and when you let the clutch out, the pressure plate will once again engage the clutch disc and you'll be in gear.

There are a number of shafts (3/Trans input/output shafts and countershaft) in the m/t containing numerous gears with varying ratios. All gears in the m/t are always moving. Really just kind of spinning and spinning until they become engaged. A shift fork is responsible for selecting the desired gear. When you select a gear, the shift fork engages a gear and it basically locks it with the trans output shaft. The gear on the trans output shaft will turn a corresponding gear on a countershaft which turns a pinion gear, which turns a ring gear, which turn the wheels.

Take a look here:
http://www.ratwell.com/technical/Transaxle/002-SideCutaway.jpg

The red shaft on the right in the input shaft, the orange on the left is the output and the shaft below the orange is the countershaft. The large brown gear next to the white circle under the red input shaft is the pinion gear.

There is a lot more to it than that, but thats the jist.

An automatic transmission...does the same thing...execpt automatically. Valve bodies, fluid pressure, etc help accomplish this.

 

http://www.youtube.com/watch?v=jk_QxHQHM1s

 

^

Dinglearm...hehehe.

 

Don't forget the torque converter. It's a turbine. The engine turns one impeller which forces fluid into another impeller, which is connected to the input shaft of the transmission. The input shaft turns a hydraulic pump and a series of planetary gears which change gear ratios based on which part is held by a clutch band. Disc clutches are used as well to change gear ratios.
All of this is made possible by careful control of hydraulic(transmission) fluid. Pressure must be closely regulated and ported to provide smooth shifting.

 

wikipedia actually has a fairly simple description of each type to get you started.

 

To add to this and clairify for the OP, a Torque Converter is only used with Automatic Transmissions.

I had torque converters explained in a very understandable terms to me once. Think of 2 fans facing each other. 1 fan is plugged in, one is not. When the plugged in fan is turned on and air flow happens, it spins the fins of the 2nd fan.

 

I've had transmissions apart, for an auto, between 400 and 600 moving parts is my guess.
A manual I would guess less than 200.
But it depends how you count. Is a roller bearing on moving part, or 20?