How to Troubleshoot & Replace Whirlpool AP6007401 / WP240309-2 Worm Gear And Bracket Assembly

I guessed a gear was stripped. After looking up the part and seeing there was an attached video on how to replace the gear, I thought not too hard. So I tore down the mixer and found the worm gear stripped. Before I went further I ran the motor to check for a bent shaft and cleaned the teeth on the shaft to make sure they were not damaged. All was okay so I ordered the worm gear & bracket assembly along with a new gasket. I am not sure if the old one was already broke or more likely I broke it in prying the two halves apart. You might put a mention about the gasket in the video as my mixer didn't come apart nearly as easy as in the video and required some careful prying. After I ordered the parts while I waited their arrival, I cleaned all the old grease out of the mixer. When I got the bracket assembly I decided to use to old bracket because the new one didn't have the dowel pin on top. Instead it had a cast pin that was not a tight fit. So I swapped the gears between the old and new bracket greased everything up good and reassembled. Another thing came up during reassembly. I had put a goodly glob of grease in the top bushing of the vertical center shaft and experienced hydraulic locking preventing the two halves from completely going together easily like I thought they should. As soon as I pulled them apart I realized that all the grease could not easily squeeze out and I wiped the end of the vertical center shaft off and that removed the last traces of the old grease and enough of the excess grease that the two halves went together like they should on the second go around. knowing now what was causing the problem I could have just use the screws to pull the halves together but I didn't want to force it together not knowing why this time it was being difficult when I had no problem with the shell while I was working on the mixer awaiting the parts. After I had the mixer together and before putting it back on the stand I did a test run. Everything ran so back on the stand it went. Now I just need a bowl and to decide what to do with 3 Kitchenaid mixers, hers, mine, and now the street rescue. I am going to say the project took 30-60 minutes but I actually spent a lot more time, A) I shot the circlip into the air, it fell to earth I knew not where (found it after looking and looking when I pulled my sock off and it fell to the floor) B) going after all the old grease in the mixer as I put in an upgrade grease of a different type. 

Checked out You tube video. Easy tune up. One gasket was damaged and I did not notice that the brush holders has no brushes. I believe a quick call to Appliance parts pros will fix this, besides I need a few more parts. I expect to get another 20+ years from this KitchenAide mixer, once repairs are competed. Watch out for the single lock washer located on the rear upper housing screw, you don't want to lose this! 

Used your video to dismantle mixer. Grease is separating and leaking oil. After grease is cleaned out I found the mixer didn't need any of the parts ordered. Worm gear looked brand new. Found out later that the mixer sat unused in a hot Texas garage for 2 years. Heat destroyed the grease. Replaced grease and put back together. Will keep parts for the next one I find. This little project was a lot of fun. Tools used Various screwdrivers scissor clamp to pick up parts punches to remove/insert pins brush with heavy nylon bristles to remove hardened grease retainer ring pliers lots of paper towels mineral spirits to remove grease - avoid motor area 

The parts I ordered from Appliance Pro got her back in business for making bread, cookies and other baked goods. The mixer is her life line for baking. 

I replaced the worm gear bracket and gear 

Replaced the phase control board and worm gear. While I had it apart I cleaned it out and replaced the grease which was breaking down and dripping. 

I used one of the many youtube instructions to fix it. Easy 45 minute fix. 

Search the internet and found out that worm gear was a common problem.Took the mixer apart to verify and confirm the worm gear was the problem. Worm gear has some worn out teeth showing once removed. Ordered the parts from you( Appliance Parts Pros.com). Installed the new worm gear, cleaned it up to remove grease during repair and plugged it to the outlet. The result, it worked. 

As preventative maintenance, replaced worn worm gears and re-greased two units used in a bakery. All grease must be removed if contaminated and replaced. Also, the repair requires snap ring pliers to remove main shaft clip. 

Replace Worm gear assembly