I have the same transmission issue you describe in my 2002 Focus. I'm pretty sure it was caused by the clutch master cylinder leaking fluid down the clutch, making it slippery. My foot slid off the clutch and slammed it into gear while it was revved too high. I believe my motor mount broke at the same time (since replaced that). I've been driving with the problem for a couple years. I don't think you have to worry about it becoming undriveable.
If you get the right rpm there will be very little grind. (the same way you would if shifting without using the clutch)
If you start in 2nd off the line you'll eliminate the shift to 2nd grind.
According to the focusfanatics forum, there's a better transmission oil than what ford stuck in it stock, and they've even switched recommendations. It supposedly helps eliminate some of the grinding people have had.
Just by driving carefully I've increased my focus's mileage to 36 mpg and after inflating my tires to max sidewall psi I'm looking to possibly get 38 mpg on this tank. It would be interesting to see what it would do with all your mods.
Originally Posted by HydroJim
This is good information. Definitely something I will take into consideration when I'm rebuilding my transmission.
Any guess what kind of MPG improvement I would get, or is it pretty random?