OK, I'll heed your advice from the earlier post and stop pushing through the resistance to downshift into first. I take it the wear on the synchronizers occurs even if I don't release the clutch until the car is at a very slow crawl (even slower than when I shifted into first)?
That's correct. If you feel resistance in the shifter, it's because the synchronizers are basically overworking themselves, for lack of a better term. They are working to try and match shaft speeds (in the gearbox) and allow you to move the shift level into the gear you're attempting to shift into.
OK, so my options are:
1. wait until I'm going slow enough that the gearbox offers no resistance to moving into first
Yup, but at that point you'll likely be moving very slowly... On my car, it's easy to get into first only if I'm stopped or barely moving at all, maybe 1 or 2 mph at most.
2. move into neutral as I come to a stop
Yup, that's what I usually do. If I'm in the mood to downshift, I'll downshift all the way to 2nd gear and then just pop the trans into neutral right before I stop completely, at which point my revs will be just under 1,000 RPM.
3. double clutch downshift into first. Is rev matching needed if I'm moving less than 10mph in second and double clutch shifting into first? Also, wouldn't the gearbox offer resistance when shifting from neutral to first if the car is still moving?
Hmm.....I rarely double clutch anymore. Back when I had worn out synchros in my old cars, I used to double clutch quite often because it was the only way to avoid the nasty synchro grinding sound. If you double clutch into 1st gear, the shifter should easily move into 1st gear while you're still moving forward. The reason is because you're physically doing the work that the sychronizer would have done otherwise by moving the shift level to neutral and re-engaging the clutch. This will match the shaft speeds and allow you to select 1st gear without the synchronizer having to do its job. Give it a try and let us know how it works. I believe it should work just fine for you.