Guru
Joined: 09/08/2007
Location: AustraliaPosts: 4406
| Posted: 02:34pm 26 Nov 2012 |
Things have changed quite a bit since the old "slush box" automatics.
These days most automatics are controlled by a computer which opens and closes solenoid valves in the transmission to change gear. All those passages, balls, springs, valves and control diaphragms in a maze of passages that used to be located in the pan under the auto transmission are no longer there.
A fluid filled torque converter can never by itself completely lock up solid with zero slip.
In an effort to boost fuel economy, the auto manufacturers started fitting a mechanical friction clutch directly across the fluid torque converter which CAN be locked solid totally eliminating any converter slip, by totally bypassing the fluid coupling.
Notice that there are two concentric splined inputs to this "electronic" automatic gearbox.
One is directly coupled to the engine crankshaft, the other coming out of the back of the fluid torque converter.
The gearbox can internally select either as it's input.
Cheers, Tony.