J.T.L.

[TOI=Transfer Of Information]
I've been driving manuals for 10+ years/ 200k+ miles with no transmission problems and only 1 clutch replacement on my 83 Prelude @ 186k (none on my 1990 CQ, even after 209k).

I don't speed shift, I don't street race, I don't abuse the car, I don't rest my hand on the shifter, I press in the clutch; I drive the car like a normal car. My shifter has always been stock. OCCAISIONALLY I need to get out into traffic or get into an opening in another lane and I need to shift quickly and get moving, but when I do so I'm making a normal shift quickly, I'm not slamming the shifter or jamming it into gear. Probably 70% of the time I'm driving this car in a non-sporting manner.


Synchros keep the gears turning at rpms that somewhat match the input shaft, so that when you shift the gears mesh correctly, right?

Are they synchronizing all gears all the time 'just in case', or, for example, do the 1st/2nd synchros only 'activate' and start synchronizing those gears when you pull the shifter to the left into the neutral position between 1st/2nd?

Does pushing the clutch in 'deactivate' the synchros? It should because the clutch should totally disengage the engine from the transmission so there would be no rotational energy to keep the synchros spinning.

What are SPECIFIC actions during the shifting process that stress the synchros?

What SPECIFIC actions during the shifting process can be done to 'baby' a car that may have been designed with delicate or fragile synchros?

J.T.L.
02 S4 Santorin/Silver/6 speeds all over the tech's workbench

pattersom

<ul><li><a href="https://forums.audiworld.com/s4/msgs/1207000.phtml">https://forums.audiworld.com/s4/msgs/1207000.phtml</a</li></ul>

MachtigAvant (v3.0)

also used the synchros with the new alloy.

S4_Cinci (I S'edTFA)

explanation of how a manual tranny works with an animated diagram and everything.

The tranny connects to the engine via the flywheel and the clutch (includes pressure plate). Clutch plate connects to the input shaft of the tranny. Input shaft of the tranny connects to the gears. Gears are on an idler shaft. Gears connect the input shaft to the output shaft via the idler shaft and dog gears. OUtput shaft connects to the drive shaft, and that is connected to the wheels via the quattro system (3 differentials).

Too hard to fully explain in words, but anytime the input shaft and output shaft speeds are not perfectly matched, you are putting some stress on the synchros (they match the idler shaft speed to the input shaft speed and ultimately to the output shaft speed via gear reduction). If everything was perfectly matched, you wouldn't need the synchros (many racing manuals don't use synchros). Double clutching can help, but takes a lot of time and effort to do well. It mates idler shaft and output shaft speeds (pretty sure, could be wrong).

If you are shifting with your fingertips (almost imperceptible to no resistance at all), you are not wearing the synchros any more than necessary. If it takes some effort the synchros are forcing the much great mass idler shaft to come either up or down in speed to match the input/output shaft and this causes some wear.

Someone else can or will explain it better than I have (and possibley correct my mistakes), but spend some time on the web site I suggested and that should give you some good ideas as to how to "baby" your synchros.

BTW, our tranny's synchros are very soft and quite complex to insure precise gear meshing; almost too soft and complex and while they do protect the gears and shafts, the syncros themselves are sacrificed and the resultant bill is still extrememly expensive. Possibly over-engineered...Hope this helped somewhat. Sorry for any conceptual errors as I was trying to do this quickly! 8^)