On my 95 k2500 with the NV3500 when up shifting from 2nd to 3rd at 25-35 mph I get a grinding sound when I let the clutch out. It goes into gear fine but will have a slight grind to it when the clutch is engaged. Would this be a syncro problem? If I up shift at 20-25 mph I haven't noticed it. It doesn't do it for long after its just when power is reapplied to the trans. Ive never had a syncro problem before and I know these trans have issues with the 3rd gear one.