do automatic transmissions use a flywheel? if so, what for? also if so, is it the same as the manual flywheel and what if any advantages would there be from installing a lightened flywheel?

 

Autos have a flywheel, called a "flexplate" in this context. Like a manual transmission flywheel, it is secured to the end of the crankshaft. The flexplate has three functions; the ring gear for the starter is welded on the outside diameter, it helps to balance out engine vibrations, and it is a connection between the transmission torque converter and the engine allowing flexing. A flywheel and flexplate both serve to smooth out the power pulses from the motor and promote smooth low speed operation (both by virtue of their mass). But the flywheel also serves as a friction surface.

Rich

 

Well stated Rich .

Dave

 

i agree, very well stated

i would like to add if it is not clear
the flexplate/torque converter, and the flywheel/clutch perform the same functions,

like previously said ring gear for starting, means for connecting engine to transmission

a clutch is a lot lighter than a torque converter, in order to keep rpm's up between shifts a heavier mass is needed, which is why flywheels are usually heavy, flexplates however dont need very much weight because the fluid filled torque converter has the desired mass