How Does The Mmt Transmission Work?

[larryalf]

I don’t think Toyota offers any cars with this type of transmission in the US. I have been reading and it seems to be a cross between an auto and manual trans. If I wanted to drive it in auto mode what do you do? Do you just hit a switch and the car shifts by itself just like an automatic transmission? Since there is no clutch how do you shift in manual mode? Do you just let off the gas and shift to the next gear? Please enlighten me.

Thanks.

[GIDDLEPIN]

Here you go Larry CLICKY

It's a sequential type of transmission, that should help explain

Les

[larryalf]

Thanks GIDDLEPIN.

That’s pretty cool. So there really is not any fully automatic mode associated with MMT. It’s really just a pseudo manual mode that takes the hand/foot coordination of a manual transmission out of the equation. I could just see myself driving an MMT equipped car and jamming my left foot onto the non-existent clutch. That could take a while to get use to.

One more question though, if I may. When I drive a stick many times I will just through it into neutral and coast to a traffic light and then put it into first gear when the light turns green. Now, if I’m driving an MMT (I noticed on the gearbox that there is only a plus and minus sign) and I’m in fifth gear and come to a traffic light will the transmission reset itself to first gear or do I have to tap the shifter 4 times (the minus sign) to bring it back down to first gear? Is there a way just drop it into neutral without having to go sequentially through all the gears?

Thanks again.

[GIDDLEPIN]

Found this write up that should help. (not by me ;)

Having owned & driven both an '01 5sp and an '03 6sp SMT, I would say the later model is the better sorted one. Changes are smoother, and on change over day were noticeably quicker than the early model. The automatic downshift pattern for coping with low-speed driving or major brake abuse/emergency stops is also much improved, as it automatically goes from the current gear (3, 4, 5,or 6) to 2nd gear at a pre-determined low speed, then down to 1st as you pull to a stop. This makes being lazy very lazy indeed when on, say, the M25. In similar circumstances, the old '01 used to drop to bottom gear with the clutch disengaged, then bang (literally) the clutch back in as soon as you picked up the throttle at anything above slow walking speed. Brutal in traffic, and it made you look like a chump, but probably the 'correct' solution for driving away from traffic. The new 2nd-then-1st automatic downshift pattern is a noticeably more pleasant experience.

As for speed of shifts; they are probably slower than someone ragging a manual, but are always equal and predictable in terms of time taken. Shift speed is definitely quicker than an average driver on an average day in a manual car, and certainly quicker than I can make in a manual car. The '03 is faster and smoother on upshift than the '01, but both early & later models get equally confused if you don't use the throttle in the correct way when changing - a slight lift will always speed things up. Too much or not enough lift will cause the gearbox to 'think' about things for a bit longer before giving you the next gear. This usually manifests itself as the clutch engaging slowly and with a little bit of slip in my current '03 model. Disturbingly, this makes it sound like a CVT gearbox as the revs momentarily rise but are not translated into immediate forward motion.

One other point of note is that it was not unusual to find the early models struggling to get 1st or reverse gear. Certainly, with mine, this could be 3 or 4 times a week and would require much to-ing and fro-ing with the gear lever to find a useable gear. The problem could occur any time you selected neutral - e.g. in traffic, 3-point turns and so on. The '03 is much, much better than this. It still happens occasionally, but when it happens it is usually just after the car is started, and re-selecting neutral and then the required gear always fixes the problem first time.

Les