4K5SSOB0 KitchenAid Mixer - Instructions

First i went to the Kitchen Aid web site and found a video on how to take a part the mixer. Followed the instructions from the video and it was very easy. The grease in the machine was black so i cleaned it out of the transmission and repack it with hi-heat wheel bearing grease that i got from a auto parts store it took about a 1/2 lb. then put the gasket in and back together and put the o-ring on. Have run for awhile and it is ok. Want to say that these are very well built machine.

Found control backplate out of adjustment. Should be nominal 3/8".Broken speed control spring which attaches to backplate bottom.
I recommend Loctite Blue to complement locknut's when adjusting RPM of "Stir" speed

I watched a video on how to replace the worm gear. When I opened the mixer I noticed a small screw laying in the grease. I removed as much grease as I could and could not find anywhere that the screw would have come from. All the gears turned and looked fine so I replaced the grease put the mixer back together and it worked fine. I am thinking the small screw must have somehow fallen into the mixer when manufactured. So proud of my 70 year old self for getting the job done.

Repair went well after I figured out how to dis-assemble the mixer. Used straight & phillips screwdrivers and a small hammer & punch to drive out 3 pins. Ordered part# PS734233 pinion & shaft as shown in the parts page, it arrived on schedule, received part # 240210-2. Only problem was the new pinion had 10 teeth, the old/failed pinion had 11 teeth. Could not learn from anyone I called at PartsSelect or Whirlpool if the 10 tooth pinion was the correct part to use.
The teeth appeared to mesh with the mating gear,
installed the new pinion, reassembled and it worked fine. Not sure if it made a noticable difference in the output shaft speed.

I replaced the phase control board because the mixer had only
one speed and was surging. I noticed from other posts that it
is important to note the setting of the speed plate before you
remove it in order to remove the phase control board. Also be
careful removing the associated 'slip-on' terminals as it would
be easy to damage the speed plate. If I ever do this again I
will go ahead and replace the speed plate, probably the cheapest
item to replace. The operation was a success and the mixer is
back in business. Thanks.

I watched a YouTube video all the way through, then watched each segment and followed along with the video. It was messier than the professional repair guy, but it worked out fine. This is not a difficult repair when you can watch a video and follow along. It saved me about $130.

Used youtube movies to disassemble the mixer and found that the gear was stripped. I kept the screws in labeled ziploc baggies so I wouldn't forget which screws went where. Once the part arrived, it was very simple to replace the gear. I regreased the mixer and then reassembled. The trickiest part was how greasy everything was! It was also hard to get the pin through the beater hub - I found a video that suggested using a very slim screwdriver to thread the hole before inserting the pin. This was the most involved part replacement I've done on my own, and it was very satisfying to get my mixer back in working order!

Took each area apart. Replaced the gear and reassembled it.

INSTALLED PHASE CONTROL BOARD AND SPEED CONTROL PLATE, BOTH AT SAME TIME
Your DYI video was helpful, especially holding the spring with a cloth. Also good for fine tuning to get the speed exact

watched how to repair

I watched the university of YouTube videos, and followed their instructions.

Followed web site's videos. One step left out of video.

Dismantled the mixer, took photos, and re-assembled unit.

You tube has great instructions! I would suggest when you buy a part to let customer know that they need a food grade gear grease ordered to complete the reinstall of all gears and body parts!

replaced gear, and brushes.