Please read my response to
another jointer problem here, and heed that advice.
In your case, part #28 is the lock screw/bolt, and part#27 is the height adjusting allen screw. (See
parts diagram here.)
I haven't worked on your particular model, but if the instruction manual is any good, it will help you with this task... for that
see this link.Make sure you unplug the jointer before working on the knives.
As you retighten them, make sure the knife is centered from side to side so the cutterhead will rotate without binding, and gently snug up the lock bolts before adjusting the height with the allen screws. Hold pressure on the magna-set, if you have one, so it doesn't move as you raise the knife adjuster up to snug against the bottom of the knife, but don't lift the knife up so high it raises the magnaset or straightedge above the outfeed table. Also make sure you are adjusting the knife when it is positioned at the peak of its arc, i.e. with the cutterhead in the proper position of rotation.
When you have the knife at the right height, tighten the lock nuts, recheck the heights, and make a final check of the lock nuts before moving on the next knife.
Work on only one knife at a time, leaving the others tight while you do so. You don't want to reduce the torque on the cutterhead unevenly.
Good luck.
I hope this information allows you to resolve this issue. If you need further assistance, please post back with a comment to this thread.
If I've managed to answer your question or solve a problem, please take just a moment to rate this post....thanks!