1990 Chevy 1500,5.7 liter 2wd,5-speed (tranmisson problems)

Hello, I have successfully replaced hydraulic clutch in my 1990 Chevy 1500 2wd 5.7 liter, 5-speed manual, my problem is when I try, to shift,into any gear it doesn't,and makes a horrible grinding and doesn't shift into
any of the gears,there was a bolt in front of the shift tower that looks like some sort of adjustment (maybe gear synchronize)that was cranked on by mistake, could this be my problem, or maybe some kind of enternal failure,or
Can it possibly be a gear synchronize. Adjustment, 5-speed. Muncie any information troubleshooting this problem please