downshift 2nd crunch, me or the tranny?

[Early_S_Man]

Ryan,

It certainly wouldn't hurt, but I have my doubts about any benefit to Borg-Warner type synchros.

[bigchillcar]

thanks, warren..just thought i'd check. i'd never read anything about its utility in those trannys either.

[hytem]

Originally posted by john walker's workshop
shifting 901 and 915 transmissions is a two step process. you have to give the syncro system a split second to work. slamming gears doesn't work well with friction syncros.

I agree, based on my short experiences with my 82SC. You have to shift deliberately, and get a feel for the synchros working. Slower than other cars I've had.

I still have trouble downshifting from 5th to 4th, and go back up to 3rd from 5th instead, on the advice of another SC owner/ mechanic. I understand it's common practice. What is your take on that? thanks.

[OT]I'd also like to know what you think about 15% ethanol gas in these cars. 10% works OK in mine, as the SC manual says. But they caution about more than 10%. I'm guessing the gas companies will probably use additives to make 15% acceptable, if they go that way. Or they will sell 10% as well.

[DJC911]

I have the 915 tranny. I get crunching in 1st and 2nd gears. First gear requires very careful technique not to crunch. Helps to be stopped. 2nd is not as bad, but don't try a 5th to 2nd downshift...even after slowing the car down. 5th to 4th doesn't crunch, but is difficult to do most of the time. And it is difficult to upshift at times after hard acceleration (i.e., top of rev range). That said, the harder I drive this car overall the better it seems to work. Of course, that can't always be done in Arizona traffic.

It sounds like I have the same problems as others in this posting...would the gear oil change help all of these issues? I was contemplating linkage coupling replacement. At some point, I am also considering gate change and short shifter, but will likely put a new clutch in first (actually, this needs to be done and I suspect may be a part of my problem).

One thing about these old Porsches...there is never a shortage of things to fix!

[Early_S_Man]

Well, the 'cheap flush' [that isn't so cheap any longer] might work or give you a bit more time ... but your transaxle needs rebuilding, and the sooner you do it ... the less likely something bad and expensive will happen while you are waiting an hoping! The bad and expensive part can include broken gear sets ...