After sitting since last use I found about a tablespoon of clear yellowish oil in the bottom of the mixing bowl- couldn[t see any on the machine itself. Is there a transmission with oil in it? I have the K5SS mixer.

Jack440 - When was the last time you used your mixer? To answer your question, yes, you KA mixer has internal transmission and planetary gears which convert the electric motor's rotation into the mixer's rotation. The internal gears are factory packed with enough grease to last a 'lifetime' (whatever that means). Depending on the age of your mixer, where it was stored (high temp possibly?) and how long it's been idle; these conditions may have let some of less viscous grease seep beyond the gasket, down the agitator shaft into your mixing bowl. What can you do? First clean your bowl and agitator shaft with detergent and hot water. If your mixer is not under warranty you can troubleshoot it yourself. Be sure you have the Parts List manual on hand. If you're lacking one, you can download it from the KA website. Click on Customer Care>Locate Manuals & Guides> Enter the 6 character model number (in your case, try K45SSW select Parts List (1) and then check to see it this matches your mixer model). You can check on page 4 & 5 for the disassembly and reassembly of your mixer, along with all the parts. It can be messy but gratifyingl. You might want to reorder the gasket for starters. Once apart you can check for any other unseemly wear and tear on the gears, etc. Good hunting... I hope this helps - Howard, Burke, VA