Tech Solutions TS8000 squeaks?

My Tech Solutions TS8000 shredder that I have had for abut 8-10 years works great but has recently started squeaking terribly when shredding1-4 sheets. Doesn't squeak in reverse. After removing the bottom cover, I oiled/greased the bearings on ends of cutter shafts, the metal gears and every place I could find that could possibly squeak. Used lithium grease (spray), 3 in 1 oil, dry lube spray but squeaking continues. It still shreds fine (am getting strips among the confetti pieces, though) but all that squeaking can't be a good thing. Any ideas anyone?