Went to Google and YouTube. Discovered that most likely cause was a stripped worm gear. Googled KitchenAid parts and was directed to AppliancePartsPros. Their website was easy to negotiate so I ordered a worm gear and worm gear bracket and bearing (just in case). The cost was so inexpensive and so was S&H. The part arrived in 3 days. I used a YouTube video to disassemble the KitchenAid, replace the worm gear (that was indeed the problem - don't knead dough with a regular spatula!), and reassemble the mixer. It works like a charm now and I saved myself well over a hundred dollars. I will definitely use AppliancePartsPros again when needed. Thanks !