Are the 'clutches' (1,2,3,4) in an automatic transmission the same as the synchromesh cones and dog-teeth system used for manual trans?

Furthermore, does an automatic transmission uses a shift-fork the same way ? And do the countershaft helical gears remain locked with the mainshaft helicals but freewheel when unengaged by dog-synchro mechanism - the same way as a manual?

 

No, absolutely not, and no. An autotragic uses transmission fluid pressure to switch between gears, which is controlled by the shift solenoids. How a standard transmission is easy - how an automagic transmission works is a bunch of wizardry that, if you really want to know about, you'll need to do some research on your own.

 

Ok, so there are channels in the Mainshaft and Countershaft that are connected somehow to an electrical valve and those channels pressurize the clutch pack which is on the shafts.

So, next questions.

1. What is the shift fork for? Only reverse I guess.
2. Would you say that the clutch packs take the full load of the motor or are they similar to the dog-and synchro arrangement in manual, where the dog engages, but doesn't truly take the load, the helical takes the load. Would you say the wet-plate clutches take the full load compared to a manual trans?

 

Reverse.

You're mistaken, the dog teeth in a manual take the full load, so do the helical teeth, and splined snychro hub. But yes they function more or less the same in an automatic, both take the full load.

Where exactly are going with all this?

 

I am trying to learn about the AT from the FSM and have a lot of questions.

So, in the AT, when the countershaft is spinning due to vehicle momentum, and a clutch pack is pressurized, does that clutch speed up the mainshaft, under no engine load, by way of the torque converter allowing the mainshaft to spin faster than the engine? And when that clutch is done using friction to match shaft speeds, then the engine is allowed to speed up, positively driving the mainshaft? So the torque converter is a one way power coupling, allowing the mainshaft to freewheel, if its speed is higher than the turbine speed of the engine side?

Also, can you say how many separate oil circuits are inside each shaft? How can there be two clutches on a shaft ( 3/4 on main ) ? How is there room for all those oil galleys?

 

the basics you could have googled this they're not very complicated once you've got it apart I bought one just to try and take it apart. That's how you learn

 

The big problem is most of those videos is they don't show how a Honda automatic works. Typically an automatic uses a planetary design. Honda doesn't, mostly so they don't have to pay patent licensing fees. In a lot of ways they share more in a common with a typical manual trans than a conventional automatic.

That being said, the way the clutch packs function (but not their arrangement in the trans) is basically like anything else. And the valve body I believe functions like anything else.

 

Well it seems honda has a special problem using no planetary system , which seems to be able to have the clutches attached to the casing, and instead has to hydraulically control the packs, floating on the shaft. how do they do that? Is there some trick i'm not seeing or are there two separate hydraulic passages circuits in each shaft, fed by the valve body feed tube,and sealed, holding separate pressure against the case bearing. What i'm especially unclear on is why there is only one feed tube per shaft.

This has some pictures. does honda have multiple circuits and the passages in the shaft like that?

http://www.jackstransmissions.com/pa...blems-upgrades

 

Does anyone agree with:

"The four-speed automatics (BAXA, MAXA, and B7XA) used in the Gen Six cars are rather complex devices. It's actually a hydraulically-shifted manual transmission.

Honda essentially replaced brass synchro rings with wet clutch packs, then hung a torque converter off the end of the input shaft, added the various servos, all governed by the ECM unit.

The intent of Honda was to essentially facilitate "transparent" operation. Abrupt shifts typically generate negative customer feedback, so HMC allowed for more "slippage" to create a seamless transition, up and down the gear range. The downside of this, of course, is rapid clutch (friction material) wear, leading to tranny malfunction/failure."

http://www.driveaccord.net/forums/sh...ad.php?t=30804

 

Honda used the typical manual transaxle gear layout to keep the transaxle on the same plane as the engine, making for a smaller overall package.

Most asian transaxles that use an "in-plane" design transaxle which will use a traditional set of gears, with a clutch hub loaded with steels and frictions to engage the gears using fluid pressure routed through from the shafts.

https://honda-tech.com/forums/transmission-drivetrain-127/automatic-transmissions-torque-converters-explained-2086594/

This article will help you understand the basic parts of most transaxles that use a "Simpson" style gear layout using planetary gears. Asian FWD automatics are too easy to understand.