KSM90MC4 KitchenAid Mixer - Instructions

Disassembled gear housing and replaced worm gear/bracket assembly. The hardest part was cleaning and working around what looked like 2 pound of grease. I will contact you again if I need parts for anything. Thanks.

Easy

dis-assemble, replace part, re-lube, reassemble, test good.

disasembled found stripped gesr assembly ordered and replaced went very smoothly. It would have been good to have info and acsess to the correct gear grease to use in a mixer / food grade but it worked out well anyway.shipping was very fast thanks

Removed three screws and lifted out old part. replaced with new part

Went to partselect, found model number, printed blow-up of mixer. Figured out disassenbly procedure. Drove out main pin removing mixer head from stand. Save pin. Drove out pin in mixer main shaft which allowed planetary head to be removed. Save pin.
Removed stainless steel bezel to expose screws for removal of bottom half of mixer body. Removed screws and carefully separated mixer halves using two screwdrivers as prybars. Care must be exercised to prevent chipping of paint on body.
Separated body. cleaned grease from gears to find actual problem. Removed broken geartooth and grease near broken part to make sure no small broken chips remained. Removed pinion shaft assembly, drove pin from gear releasing broken pinion/shaft. Save pin/
Cleaned grease from pinion shaft assembly using mineral spirits and a small brush to reveal how part could be disassembled. Ordered part immediately on-line. Part arrived 1 business day after it was ordered.
Reversed process for replacing pinion shaft. Applied fresh grease obtained from excess already in mixer, spun pinion shaft to make sure grease was properly distributed. Reinstalled pinion shaft assembly. CAREFULLY plugged in mixer and jogged motor to make sure all was free and that mixer worked. If you can repair this mixer, you should have enough sense to do this diagonistic. Keep fingers away from all moving parts, don't touch expposed electric wires. Plug in only after making sure switch is in off position. Jog using mixer switch. Make sure mechanism is free.
Complete re-assembly by following blow-up and reversing disassembly steps. It may be good to write down you disassemblly procedure if it is possible that you won't be reassembling within a day or two.

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.

Unscrewed the existing screw cap, put the new one in place, replaced the screws. So easy!

Simply removed damaged gears. Very simple to do. Ordered gears. Replaced gears. Both working well ( so far. ) Machines are easy to dismantle. Just be sure to put the screws back in the holes you took them out of when dismantling...no lost screws. On the smaller model, took pictures of the wire positions to be sure they were replaced in the proper order. Larger model had no wires to remove.

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.

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.

Simple fix actually. UNPLUG mixer and remove the one screw on top that holds on the back. The Phase control board sits under and behind the paper insulator and "switch" assy. Remove the 4 wires with a pair of needle nose pliers, the one screw holding it to the back of the mixer and install the new one in reverse order.

I simply inserted the new beater into the mixer to see if it scraped the sides of the bowl. It fit perfectly and didn't scrape the bowl like the old one did.

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.

had to replace the outlet strip and relocate the mounting screw,,,,wiring cord to the mixer was super correct and had to simply follow basic wiring (black to black,,,silver to silver,,,green to ground) ,,, the cord came with the correct mounting bushing already on the cord. Thx a bunch!