KSM90MC4 KitchenAid Mixer - Instructions

Watch U Tube video. Take care to keep track of disassembly. Hard part was to have 4 types of screw drivers to fit the different screw heads. Be sure to clean broken gear clogs out of the grease. Parts select lady was a great help. Download Parts select diagram for extra help. Time and patience!

Removed the rear cover to inspect the speed board. Replaced motor brushes and noticed the motor body nuts were loose and 1 was completely off. Cleaned up speed board and replaced the motor body nuts, tightened with nutdriver, adjusted speedboard governor screws and with new motor brushes worked like a charm. The very rough sounding motor noise was gone and the mixer has not operated so quietly ever.

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.

With a screw driver remove the screws holding the old base in place. With a flat head screw driver carefully pry and remove old mixer base. With 600 grit sandpaper clean and make smooth any burrs or rough spots in the mixer base recessed area. You can use some light grease and coat the outer edges of new mixer base and place in the now cleaned mixer base recessed area. The new base maybe a tight fit and not be fully seated in the recess. If a tight fit, place the piece of 2x4 piece of wood over the new part that is in the recess and carefully tap the base home using the sledge hammer. Check to see, if the base is fully seated. If not fully seated, tap again When fully seated replace the screws. You may have to adjust the height of the stand mixer head with mixer paddle attached for proper clearance between bowl and paddle. See your mixer manual for adjustment procedure

I watched a short video on replacing the worm gear, although I did not know what the problem was until I watched the video. after the video ended I took the mixer apart and found the problem located a parts number an placed my order. got the part in one week put in the new part in about 20 minutes and it work like new. and the price was very reasonable

The new part was too large for the replacement job, but we used the self tapping screws that came with the mixer and screwed them in from the bottom to open the holes a little more since the original screws were to short to hold the new plate. Then we replaced the screws with longer screws and that seemed to do the trick!

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!

Removed back cover, disconnected the 2 push-on connectors, removed ground wire screw. Reversed the process to install new cord.

I had a sourdough batch get into the space where dough hook attaches and it got so stuck that nothing - not hot water baths, not pliers and screwdrivers got the dough hook released. I had to open up the mixer following partselect you tube instructions and replacing the parts. What was confusing to me at first is that my 45 year old mixer had an extra screw on top of the shaft that no longer is there for newer models. It took me longer than I am willing to admit to figure that the extra screw is not the result of me skimming the instructions - the original shaft and dough hook went to a friend who broke it attempting to disengage the two parts (the dough turned out to be a very strong form of glue!). The piece is working like new. I preferred the agitator shaft with a spring to hold the end piece tighter, but the new set up without a spring works just fine.

The brushes are located on each side of the tilt head of the mixer. I used a screwdriver to remove the screws, removed the brushes & replaced with the new ones. Runs great again!!

The shield works sufficiently. Note that the shield is not a continuous circle as shown in the picture. This actually can be an asset because it can be installed or disassembled without stopping the mixer of having to lift the head while running.

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.

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

Replaced gasket and O-ring. Problem solved. POC (Piece of Cake).

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