torque converter

[ehulst]

Hows the torque converter work....i kno it has to do something with the turning of the tranny from the engine but whats inside the converter it self....my macanic said there is clutchs and shit in there and if dirt or anything gets it i would have to bring it to a transmission shop and have then untac the tac welds and re do all the clutches....is it really like easy to get dirt in there or something?

[smufguy]

ever heard of howstuffworks.com? well here you go. hope this helps

The Basics

A torque converter is a type of fluid coupling, which allows the engine to spin somewhat independently of the transmission. If the engine is turning slowly, such as when the car is idling at a stoplight, the amount of torque passed through the torque converter is very small, so keeping the car still requires only a light pressure on the brake pedal.

If you were to step on the gas pedal while the car is stopped, you would have to press harder on the brake to keep the car from moving. This is because when you step on the gas, the engine speeds up and pumps more fluid into the torque converter, causing more torque to be transmitted to the wheels.

how they work

http://static.howstuffworks.com/gif/torque-part.jpg

As shown in the figure below, there are four components inside the very strong housing of the torque converter:

* Pump
* Turbine
* Stator
* Transmission fluid
http://static.howstuffworks.com/gif/torque-cutaway.jpg

The housing of the torque converter is bolted to the flywheel of the engine, so it turns at whatever speed the engine is running at. The fins that make up the pump of the torque converter are attached to the housing, so they also turn at the same speed as the engine. The cutaway below shows how everything is connected inside the torque converter.

The pump inside a torque converter is a type of centrifugal pump. As it spins, fluid is flung to the outside, much as the spin cycle of a washing machine flings water and clothes to the outside of the wash tub. As fluid is flung to the outside, a vacuum is created that draws more fluid in at the center.

http://static.howstuffworks.com/gif/torque-pump.jpg

The fluid then enters the blades of the turbine, which is connected to the transmission. The turbine causes the transmission to spin, which basically moves your car. You can see in the graphic below that the blades of the turbine are curved. This means that the fluid, which enters the turbine from the outside, has to change direction before it exits the center of the turbine. It is this directional change that causes the turbine to spin.

http://static.howstuffworks.com/gif/torque-turbine.jpg

n order to change the direction of a moving object, you must apply a force to that object -- it doesn't matter if the object is a car or a drop of fluid. And whatever applies the force that causes the object to turn must also feel that force, but in the opposite direction. So as the turbine causes the fluid to change direction, the fluid causes the turbine to spin.

The fluid exits the turbine at the center, moving in a different direction than when it entered. If you look at the arrows in the figure above, you can see that the fluid exits the turbine moving opposite the direction that the pump (and engine) are turning. If the fluid were allowed to hit the pump, it would slow the engine down, wasting power. This is why a torque converter has a stator.

http://static.howstuffworks.com/gif/torque-stator.jpg

The stator resides in the very center of the torque converter. Its job is to redirect the fluid returning from the turbine before it hits the pump again. This dramatically increases the efficiency of the torque converter.

The stator has a very aggressive blade design that almost completely reverses the direction of the fluid. A one-way clutch (inside the stator) connects the stator to a fixed shaft in the transmission (the direction that the clutch allows the stator to spin is noted in the figure above). Because of this arrangement, the stator cannot spin with the fluid -- it can spin only in the opposite direction, forcing the fluid to change direction as it hits the stator blades.

Something a little bit tricky happens when the car gets moving. There is a point, around 40 mph (64 kph), at which both the pump and the turbine are spinning at almost the same speed (the pump always spins slightly faster). At this point, the fluid returns from the turbine, entering the pump already moving in the same direction as the pump, so the stator is not needed.

Even though the turbine changes the direction of the fluid and flings it out the back, the fluid still ends up moving in the direction that the turbine is spinning because the turbine is spinning faster in one direction than the fluid is being pumped in the other direction. If you were standing in the back of a pickup moving at 60 mph, and you threw a ball out the back of that pickup at 40 mph, the ball would still be going forward at 20 mph. This is similar to what happens in the turbine: The fluid is being flung out the back in one direction, but not as fast as it was going to start with in the other direction.

At these speeds, the fluid actually strikes the back sides of the stator blades, causing the stator to freewheel on its one-way clutch so it doesn't hinder the fluid moving through it.

[smufguy]

Hows the torque converter work....i kno it has to do something with the turning of the tranny from the engine but whats inside the converter it self....my macanic said there is clutchs and shit in there and if dirt or anything gets it i would have to bring it to a transmission shop and have then untac the tac welds and re do all the clutches....is it really like easy to get dirt in there or something?

it would be much easier to replace it with a new one than trying to fix it. no dirt would get in it, if its been maintained right. besides, no dirt period. Its not open to the environment so there wont be anything like dirt in it besides deposits from the heat produced due to breakdown of the fluid and the parts itself. you can extend the life of the torque convertor/tranny by keeping the fluid temperature low enough. So i would say if you do a lot of higway or even city driving, get yourself a tranny cooler, they are cheap thesedays and you can grab one at summit for about 50 bucks and they are pretty soild cooler. It will be an afternoon job and it will look wicked cool hanging on your riight or left fender wells (right behind the bumper).

it looks like this

http://static.summitracing.com/global/images/prod/large/bmm-70268_w.jpg

click here for details (http://store.summitracing.com/default.asp?target=esearch.asp&N=110&Ntk=KeywordSearch&Ntt=transmission+cooler&x=0&y=0)

[A20A1]

Also note that when you turn hard in one direction you get more pull and in the other direction the trans seems to slip. This is cause fluid is forced out or in of the TC.

I like coolers... I have 2 B&M's
http://www.3geez.com/attachment.php?attachmentid=3095&stc=1

You should hook one up to a fan, and the fan needs to be always on if you are only using one cooler, or it could have a thermal switch... I used two cause I didn't like the idea of relying on radiator fluid to cool the trans fluid.

[A20A1]

I would have your TC rebuild by LEVEL 10 instead of going to a regular mechanic. If the price is close to eachother... since you'll get a performance upgrade as well.

[ehulst]

IC its just that i bought this awhile ago and i found some dirt in it..make a long story short that my manic wont put it in cause he saw grass and mudd stuff in where the output shaft goes and there was like transmission fluid and such in there but he wants me to spend like 100 bucks on rebuilding it then he'll put it in.......I mean i saw it my self and felt it my self that there was junk in there but i tipped it upside down and it all disapeared a little of it came out with the left over fluid....so i'm just confused....and my parents want me to have a pro Tranny person down in Portland look at it.....but i don't wanna spend the money if it wont hurt it any

[A20A1]

I didn't know the TC was tac welded, I thought it was seale much much better then that... It's not easy to get dirt in there, unless the car was stuck in a big flood.

[ehulst]

yeah i just cleaned it up with my air compressor and a flat head screw driver and a paper towel...and yeah mine was tac welded 5 places all around......i ant touchin it cause i ant got a welder......