Technical explanation of Transmission?

[muffin_man]

Well, it is unquestionably an interesting transmission, but I question the idea that it is optimized for maximum efficiency.

I'm sure it's more efficient (and lighter) than an automatic would be, but it also doesn't shift as smoothly or quickly as most automatics, and it doesn't provide the control, fun, or speed of a manual.

The fact that my test drive and every test drive on this forum starts with a salesman apologizing for the transmission - one way or another - doesn't help.

Then again, considering the 18 month waiting list, the car obviously didn't need to launch with a manual, it is apparently as good as it gets for the moment. That said, the transmission is the big question mark with this car - adding a 5-spd would be the biggest improvement they could make.

And as for my original question, and diagrams, or technical docs of how this transmission works?

[a2jack]

This Trans is compromise of cost and weight. It is a re-engineer of the euro 6 speed. The clutch is activated by a proportional electric motor to enable it to engage smoothly. The ECU controls it all. Although, at times, it feels rather dumb.

One needs to learn a pattern to happily drive it. The one problem I have is, It's my wife's car and I don't drive it everyday. After years of intuitive shifting (my DD is 5sp stick) I must always think about the shifts when I drive this car.

Overall the car is a fun machine, and after 8,000 miles we can say the Smart is well worth the money.

[Fredvon4]

muffin man... no tech docs or much internal info will ever be known...Mercedes Benz is one of the most tight lipped manufactures there is...I doubt Mitsubishi even know much about the trany..control.... mechanically we will know a lot but electronically we will know very little

That said some educated guesses are possible from us motor heads with experience in rebuilding motors and trannies...

This box is a fully synchronized 5 speed with 4th and 5th being both over drives..0.943:1 and 0.707:1 respectively

The final drive differential is open spool (no limited slip) and the ratio is 4.59:1

The final drive is integral to the trans-axle and gear driven off the main shaft

This trany has a standard clutch, pressure plate, fork, and throwout bearing that is electro mechanically activated by the ECU

To be able to do what it does I assume these facts:

There is a throttle position sensor
There is a separate WOT throttle position sensor
There is an input shaft RPM sensor
There is a clutch position sensor
There is a gear selection sensor
There is a final drive rpm sensor
There are two Lambda (O2) sensors one is a Bosch Wide Band device

We assume the program is designed to mostly favor emissions and economy over performance

We know the ABS, Electronic Stability Program (ESP), and the Traction Control programs all interact with the engine and transmission management programs in the ECU

How this all works is magic...

I hope you got something from my assumptions and facts

I can not tell what you are after in your quest...

[Smart Magus]

Hey Muffin man. I can give you all the detail. Contact me as postmaster at AutoDiagCart dot com for the detail. Please have your vin and the specific system you are interested in. I would love to help.

[Godfather]

I named the squirrel running in the cage in the back of my smart. He's Merlin. He works for peanuts. And never complains................

[jetfuel]

woah...you got the upgraded version...where can I trade the hamster for a squirrel

jetfuel

[Neonspinnazz]

I'm using alternate fuel for the Envoy. I use Freshman power. They work for Pop Tarts.

Oh, not again. The power went out again, I'm glad the modem and my laptop has a battery.

[SmartTech]

there is a ton of info on the transmission and operation in the 2008 tech manual on my down load page:Downloads. pages 48-64 are all about the transmission and how it works and is controlled.

[Bill Marshall]

I wonder how this transmission compares with the "automatic stick shift" tha VW had on its original beetles 30 years ago.

[BigWarpGuy]

Here is a site - ask.cars.com - with an explanation of the automated manual transmission. Here is a Wiki site on the semi-automatic transmission. Perhaps these sites could be of some help?