Question: Is the "grinding" happening while you're trying to pull the lever into second, or is it when you let out the clutch?
I've had the latter happen when trying to engage reverse. Basically, I have a hard time getting the lever to move back as far as it should, and basically it would appear I haven't fully engaged the gear when I let the clutch out... buzzzzz.
If this is your situation, I'd suspect there's interference between the shift lever and some other part when you try pulling the lever down and toward you.
Now, I digress... In my case, I've decided the problem was a clutch that wasn't completely disengaging. In such a case, the synchros would still be able to overcome the dragging clutch to synchronize the gears, but if the dog teeth aren't properly aligned, you're SOL (double-clutching or pushing the lever into another gear may be necessary). For the time being, I think bleeding the clutch may have cleared this up (since air in the clutch slave cylinder would result in less clutch plate travel).
I guess what I'm trying to say is, might as well bleed the brakes and clutch while you're troubleshooting... Can't hurt (unless you do it wrong).
