JDHertz11

I usually shift from 2nd to 1st as a matter of habit... but I don't really know why I do it...

Flying Finn

I slip it in 5th as that gear is used a lot less than 2nd.

MarkD

same here... glad it's not just me with the habit. Just feels better.
wonder where that came from?

race911

From the original book? Again, lots of wisdom came from him (was he one of the nicest guys an 18 y.o. with a broken 911 engine could have ever come across.....), but like with Pete most everything from his personal involvement are from the 915 and 901 days (let alone 741 and its predecessors). If you've had your hands in the pre-Borg Warner synchro trannies, you'll know why they recommended these tricks and tips. Since 99.999999999999% of everything else has used a Borg Warner synchro since synchros were introduced, I'm sure "conventional wisdom" pretty much applies to what's going on with our cars here.

1pcarnut

The point of double-clutching is not to align the gears but rather to get them turning (synchronized) at the same speed so they mesh smoothly. That is why it's especially necessary in a non-syncro gearbox. If you've ever driven say an old truck or car without syncro in first you've had the fun of grinding gears and sounding like a rookie until you learn the nuances of this. It is a learned art to get the revs just right for it to slide noiselessly into first on one of those boxes.

In our cars we have syncro rings that pretty much do this for us. But a driver who learns to double-clutch properly can get the gears meshed faster than the syncros could just by themselves. When shifting forcefully without double-clutching you will wear out the syncro-mesh rings, hence the reason our gearboxes respond more smoothly when pausing momentarily between shifts.

When coming to a stop sign, what I've found works well is to almost be stopped, (like the last 3-4 feet), put the car from 2nd into neutral, let out the clutch for a split-second (no throttle needed at this speed), then again depress the clutch and it will slide smoothly into 1st.

If traveling at a faster speed than that, then you need to learn to match your revs to the speed of the gear you plan to go to. In other words, if your next gear will put the engine at 3000 rpm, then that is what you'll need to see on the tach when you double-clutch in order to get the gears on that shaft turn simultaneously.

This is also the reason why a slippery synthetic can actually make shifting, (particularly down-shifting where there is a greater disparity in gear speed) not as smooth. The duty of the syncro-rings is to get the gears at the same speed but if oil is very slippery, the rings can't do this as well.

I'm not a big fan of going into 2nd before selecting 1st since this puts twice the wear on the 2nd gear syncros. My .02.

race911

Something else I thought about overnight--what wear IS there on a high mileage G50? Hopefully one of the experts will pop in........... I've only had my hands in 5 or 6, all low mileage units that were apart for either regearing or steel synchros. No wear. Having done (or at least broken down) 200+ 915s, I've seen those that have puked the 1st gear dog teeth in as little as 30K, mainly from maladjusted clutches. Which really became a problem starting in '77. I'm not sure even the asymmetric teeth update did much to help. Bottom line is that the cone synchro trannies we're discussing here have zero in common with the Porsche synchro units of 1986 (1988 for turbos) and earlier.