Kitchenaid professional mixer

If it is a ksm103 there should be a spring on the shaft, it should look similar to this: http://www.mendingshed.com/kacentershaft.html

When adjusting the screw you should be turning it out, which will make the beater closer to the bottom of the bowl, when properly adjusted you should be able to place a dime in the bowl, and the flat beater should just move it around barely. that would be about 1/16" in clearance.

You can adjust the mixer bowl up and down slightly. If you lower your bowl and look at the back you will see a little screw, it looks like a flat head screw and it is on the "neck" of the mixer.
You can raise and lower the bowl by adjusting this cam screw. You can tell that your bowl is adjust correctly by attaching the flat beater and put a dime in the bottom of the bowl, the beater should just barely touch the dime and move it around the bottom of the bowl.

The beater will not scrape the sides of the bowl, if you are wanting the sides of the bowl scraped I would recommend the Flex Edge Beater made by KitchenAid which is basically a flat beater with a rubberized edge which will scrape the side of the bowl as it rotates.

Here is a link to the flex edge beater on our website: http://www.mendingshed.com/kfe6l.html
Let me know if you have any other questions.
Thank you,
ColleenCustomer ServiceMendingShed.com800-339-9297

Make sure your Beater can slip in and out of the Beater Shaft
easily. Do not force the beater onto the Shaft if the shaft is bent.
If it cannot be removed easily by hand, use a soft rubber mallet
(not a steel hammer) to slightly tap the beater so it can be moved
up and down the shaft or from side to side. Then you can easily
turn the beater left and remove it from the shaft.

From Kitchenaid Manual:
To Attach Flat Beater, Wire Whip, or Dough Hook
1. Turn speed control to OFF.
2. Unplug stand mixer or disconnect power.
3. Tilt motor head back.
4. Slip beater onto beater shaft and press upward
as far as possible.
5. Turn beater to right, hooking beater over pin on shaft.
6. Plug into a grounded 3 prong outlet.

To Remove Flat Beater, Wire Whip or Dough Hook
1. Turn speed control to OFF.
2. Unplug stand mixer or disconnect power.
3. Tilt motor head back.
4. Press beater upward as far as possible and turn left.
5. Pull beater from beater shaft

Open the Transmission Housing and remove the two screws holding
the Motor. Lift it off the gears and test run it by itself. The motor
should run normally at different speeds. If it does, then you can move on
to the gears. Manually turn the Worm Gear and make sure nothing got jammed.
The Bevel Gear should turn smoothly.

Make sure your Beater can slip in and out of the Beater Shaft

easily. Do not force the beater onto the Shaft if the shaft is bent.

If it cannot be removed easily by hand, use a soft rubber mallet

(not a steel hammer) to slightly tap the beater so it can be moved

up and down the shaft or from side to side. Then you can easily

turn the beater left and remove it from the shaft.

From Kitchenaid Manual:

To Attach Flat Beater, Wire Whip, or Dough Hook

1. Turn speed control to OFF.

2. Unplug stand mixer or disconnect power.

3. Tilt motor head back.

4. Slip beater onto beater shaft and press upward

as far as possible.

5. Turn beater to right, hooking beater over pin on shaft.

6. Plug into a grounded 3 prong outlet.

To Remove Flat Beater, Wire Whip or Dough Hook

1. Turn speed control to OFF.

2. Unplug stand mixer or disconnect power.

3. Tilt motor head back.

4. Press beater upward as far as possible and turn left.
5. Pull beater from beater shaft.

Make sure your Beater can slip in and out of the Beater Shaft
easily. Do not force the beater onto the Shaft if the shaft is bent.
If it cannot be removed easily by hand, use a soft rubber mallet
(not a steel hammer) to slightly tap the beater so it can be moved
up and down the shaft or from side to side. Then you can easily
turn the beater left and remove it from the shaft.

From Kitchenaid Manual:
To Attach Flat Beater, Wire Whip, or Dough Hook
1. Turn speed control to OFF.
2. Unplug stand mixer or disconnect power.
3. Tilt motor head back.
4. Slip beater onto beater shaft and press upward
as far as possible.
5. Turn beater to right, hooking beater over pin on shaft.
6. Plug into a grounded 3 prong outlet.

To Remove Flat Beater, Wire Whip or Dough Hook
1. Turn speed control to OFF.
2. Unplug stand mixer or disconnect power.
3. Tilt motor head back.
4. Press beater upward as far as possible and turn left.
5. Pull beater from beater shaft

Hi - I've been searching for general info on KitchenAid stand mixers and ran across this so I'm throwing my $.02 in... Since KA stand mixer bases are essentially made of cast metal parts, there is a very slim chance that there is a lateral misalignment (side-side) unless it got dropped...eek! Sounds like a head height adjustment issue. Check out this from KitchenAid Conversations:

http://forum.kitchenaid.com/forums/topic.asp?TOPIC_ID=3032

Good luck.

DZII

take off the chrome ring around the rotator. remove the screws that were hiding under it. pull off the rotator and replace the "O" ring on the shaft.

you will need to open it up and check it out. sounds like a broken gear. it's not difficult to work on just remember where everything goes so you can put them back. mendingshed.com has parts and you can find how to do it on kitchenaid.com

you most likely stripped the plastic gear (Worm gear???).  This gear is designed to fail to prevent the motor from burning out under EXTREME loads (i.e. when a metal piece falls into the bowl). The plastic gear is much cheaper than a new motor.  Look around on this site to see how to get at/repair the gear.  I've found many parts on eBay.com and also PartSelect.com.