Synchros, dumb question...

[joehahn]

...remember there was always that one professor that insisted "there is no such thing as a dumb question". Here goes...what do the synchros actually do? I have been told by my mechanic that tranny may "just" need new synchros. I do actually know what "synchronize" and "synchronization" mean but when I look in all the catalogs all I see are the thin metalic almost circle things. I searched the archives but all "synchro" posts really just talked about mis-shifts, etc. What do these things actually do? Easy to replace?

TIA

joe 68 L (sportomatic)

[JWest]

http://www.howstuffworks.com/transmission4.htm

Porsche "servo" syncromesh works differently than the typical Borg Warner used in most transmissions, but basically there is a friction surface that forces the dog teeth on the gear to turn at the same speed as the slider on the shaft. When the parts are spinning at the same speed, they can engage much more readily.

The syncro bands in Porsche transmissions have an organic friction surface that seems to have a higher rate of wear than the brass rings in Borg Warner syncros. But when new, Porsche syncros have a solid, quality feel that is not notchy and clicky like BW syncros. Porsche syncros also don't shift fast.

[Allan Broadribb]

Check this out - you can even shift the gears!

http://www.howstuffworks.com/transmission3.htm

[joehahn]

AWESOME! How idiot proof is that!

Thanks guys.

[JWest]

Did you notice that it even pauses in N just like you should when shifting 901 or 915? Very coool.