Originally Posted By: StevieC
It would appear the Germans can get something right once and a while.
I like the W5Ax80, don't get me wrong. But all credit to the Germans? I would say it was at least as much the American Chrysler transmission engineers who took the German design and turned it into a much more reliable, affordable, and better all-around package. Its obvious that a lot of the features are derived from some hard lessons learned with the A-604 series transmissions (the 41TE and 42LE, dating back to 1989 and 1993, respectively). People spent the 90s bashing, often justifiably, on Chrysler's transmission reliability issues- but that's what happens when you're at the forefront of new technology development as Chrysler was at the time (too bad they're so far from the forefront these days...)
As for the other characteristics listed in G-man's post, let's see just how many of those actually were present in the Chrysler 41TE, the first mass-produced electronic automatic (yes, we all know that it had 5 years of teething problems, but I'm just talking about the features):
Originally Posted By: G-MAN
The shift schedule adapts to individual driving style, driving situation and road conditions, altering shift points based on an accelerator pedal usage, brake usage, lateral acceleration, altitude and load on the car as a result of grades.
OK, all of those characteristics were part of the very early Chrysler electronic transmissions. Definitely in place by 1994 were 1) adaptive shift points and shift firmness based on accumulated measurements of the driver's control inputs, 2) grade management in cruise control (dropping to 3rd gear on long downhills so that the speed wouldn't drift far above the set-point), 3) Torque management during WOT upshifts- fuel was cut to alternate cylinders during upshifts to limit the torque dissipated in the clutches (note: this pre-dated electronic throttle control and was the only method available when the driver's foot is hard-cabled to the throttle plates... see below)
Originally Posted By: G-MAN
Electronically controlled engine torque management provides quick wide-open-throttle up shifts and quick two-step (4-2 or 3-1) kick-down shifts that are exceptionally smooth.
This level of torque management is a truly revolutionary feature, but its not unique to the W5A. I don't actually know who did it first- GM may have beat both Chrysler and Benz to the punch. When the computer actually controls the THROTTLE BLADES, upshifts can be glass-smooth without dumping tons of heat into slipping clutch packs. Virtually all automatics on the road today have this feature. It actually went a LONG way to eliminating many mechanical failures that 90s transmissions saw because components were made lighter and lighter to improve efficiency, but still had to absorb the abuse of full-throttle upshifts from time to time. Or as a co-worker likes to say, "you CAN fix hardware weaknesses with software sometimes..."
Originally Posted By: G-MAN
Torque converter clutch slippage is electronically modulated and provides for partial engagement in Third, Fourth or Fifth gears. This results in improved shift feel, fuel economy, driveability and cooling. It can be used at lower speeds to provide benefits over a broad speed range. The system disengages as required to provide optimal performance.
Again, this goes all the way back to 1989, or at least to 1993, straight from the FSM for my wife's 1993 LH car. The torque convertor clutch began partial locking in 2nd gear, with progressively more lockup in 3rd to full lockup in 4th. This is ALSO what gave rise to ATF+3, because Dexron would cause TCC shudder during partial lockup operation.
