Double cone synchronizer

[ragingfish]

Ok, I know this is a Vibe forum, but I have to ask a general car question...I'm watching commercials for the new mazda 6, and they're touting one of the big features as a double cone synchronizer, which, i'm guessing, is engine or transmission related. What is a double cone synchronizer??? Man, cars are SO CONFUSING!!!!!!Thanks all...I've learned amazing amounts about my car due to this forum!!!

[turbotoy]

It is in the trans. I am not sure why it is better but with our race eclises you cant shift at high RPM's without them

[ragingfish]

quote: I am not sure why it is better but with our race eclises you cant shift at high RPM's without themour race what? lol

[ragingfish]

i was thinking eclipse, but wasn't sure...so, what exactly does it synchronize? i guess the drive shaft with the engine maybe?

[NSimkins]

Some related definitions from the Dictionary of Auto Terms:quote:synchronizer:A cone or sleeve that slides to and fro on the transmission main shaft and makes the gears rotate at the same speed to prevent clash when the gears are about to mesh. Whenever a vehicle is rolling, the transmission main shaft is turning and the clutch gear is spinning. Even though the clutch is disengaged, the clutch gear continues to spin until friction slows it down or stops it. Thus when the driver shifts into another gear he is trying to mesh gears that may be moving at different speeds. By using synchronizers, the possibility of broken or damaged teeth is reduced and shifting effort is lowered. A transmission using synchronizers is called a synchromesh transmission. quote:synchromesh transmission:A transmission using a device (synchromesh) that synchronizes the speeds of gears that are being shifted together. This prevents "gear grinding." Some transmissions use a synchromesh on all shifts while others synchronize second and high gearshifts. quote:synchromesh:A device in a manual transmission that allows two gears to mesh more smoothly. When a synchronizer gear matches the speed of the transmission main shaft to the speed of the gear being selected, they mesh smoothly and prevent grinding and clashing of gears. It was first introduced by Cadillac in 1928.

[ragingfish]

good info nick, thanks!now i notice it says it's found on manuals...what about autos? why don't they need a synchronizer?

[NovaResource]

Automatics don't need synchros because the gears never disengage each other. You need synchros to help to gears that aren't engaged and spinning at different speeds mesh together without hitting each other (grinding). Because an automatic trans uses "planetary" gears that are always togther there is no need. Planetary gears get there name because they are like the solar system with a "sun gear" in the center, "planet gears" (usually 3) around the sun gear and a "ring gear" around the planet gears.Planetary gears look something like this:Here is some good info to read if you are interested:http://biz.howstuffworks.com/gear-ratio ... ission.htm

[ragingfish]

Dude, that info is awesome, thanks so much!

[NovaResource]

One other thing, synchronizers are why you no longer have to "double clutch" while shifting. Double clutching was pressing the clutch twice for every shift: - clutch in - shift from gear to neutral - clutch out - clutch in - shift from neutral to next gear - clutch outThis extra clutch out and in was to get the gears spinning the same speed.