5KSM150PSZER0 KitchenAid Mixer - Instructions

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.

Followed instructions found onllne at Kitchenaid.com and replaced seals with parts obtained from PartSelect.

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.

Watched a couple of youtube videos and it was easy.

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 did exactly what the PartSelect video demonstrated after watching other DIY videos on the Internet, thus I did not remove the stand which seemed like a little too much for a simple straight forward repair. This is the second time I have replaced this gear. The first time was about 10 years ago when the bakelite gear broke on a 30 year old KitchenAid K
-45. That mixer made hundreds of loaves of bread after grinding many pounds of wheat berries. The only reason we had to replace it was that it walked off the flour dusted counter and landed on its head when my wife had her back turned. Otherwise we would still be using it. :-)
Thanks for the excellent service and instructions.

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.

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.

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

To access the interior of the mixer, I first removed the single screw holding the cup-shaped part at the rear. Then I removed the 4 large screws on the under surface of the mixer head. Next I removed the bright metal ring around the planetary gear area by prying it off. I then pried the dish-shaped part off the shaft using a large-bladed screwdriver. This exposed 5 screws on the circumference of the planetary gear. By removing them, one can pull up the gears and see into the area below. I found the worm gear had fractured. By removing 3 screws at the base I extracted it for closer inspection, checking for any loose pieces. Beware of the jelly-like grease. The replacement part goes into position, and one then follows the steps in reverse.

dissassembled mixer and replaced gear

When I took the back cover off I found two parts that "could" be the problem. The speed control plate was cracked which explained the spotty working. I ordered both parts and installed them very easily. The parts fit perfectly and resulted in the mixer working perfectly. I can't say enough about the excellent parts. They were perfect.

After stalling the mixer while mixing dough I found that the motor still functioned but the blade didn't move. I basically took the mixer into my shop along with a digital camera to record any complicated disassembly procedure I might have to deal with for reassembly and proceeded to disassemble the mixer. Once apart, I cleaned the mixer parts, removed the broken worm gear and bracket, and got online for someone that carried the replacement piece. PartSelect sent the replacement within 3 days and now it works great again.