I have a computerized Bernina & the only piece I put ONE DROP of oil on when I clean it before each new project is on the bobbin fly - the part of the machine that holds the bobbin & bobbin case. I'll bet that would take care of your klunking. If you don't want to oil anything (and I can understand your reluctance) you should take it in to be serviced. You may be doing it harm if you keep sewing on the "klunker"!