The paddle on my mixer runs too low and hits the bottom of the bowl. any ideas?

Hi ERIN. This should be pretty easy to do by yourself. The instructions for adjusting your beater to bowl clearance is in your Owners Manual. If you don’t have the original manual you can easily download a PDF version of your Owners Manual from the KA website: (http://www.kitchenaid.com/flash.cmd?/#/page/home).
Click on Customer Care>Locate Manuals& Guides> and enter the 6 character model number, in your case K$45SSW and select the file listed for your model that appears under Owners Manuals (2): K45SSWH-0.pdf (2730.37 KB) and save that file to your PC. Turn to Page 13 and you will find the instructions for adjusting the mixer head height. I have extracted the instructions below:
Beater to Bowl Clearance
Your mixer is adjusted at the factory so that the flat beater just clears the bottom of the bowl. If for any reason, the flat beater hits the bottom of the bowl or is too far away from the bowl, clearance
Tilt-Head models
• Unplug mixer.
• Lift motor head.

• Turn screw (A) SLIGHTLY counter clockwise (left) to raise flat beater or clockwise (right) to lower flat beater.
• Make adjustment with flat beater, so it just clears surface of bowl.
If you over adjust the screw, the bowl lock lever may not lock into place.
I hope this helps! – Howard, Burke, VA
If this solution has helped you, please rate it, thanks! - hslincoln