Gearbox worn, terrible noise, needs to be repaired

Sounds like a worm gear problem to me, it's impossible for the motor (armature) to move far enough to not drive the gear. There are driving pins in the system from fuse gear to paddle.
1) in the fuse gear
2) inside gearbox above planetary joining shaft to bevel gear
3) through planetary and shaft

There is also one joining the little gear inside the planetary to the shaft, doubt you'd break that one though.

KitchenAid uses a vegetable based grease inside of their mixers, it is a food safe grease. Because of this if you do not use your mixer often and over time the grease inside the mixer can begin to break down, and an oil will leak from the mixer.

What you will need to do is take the mixer apart, clean out the old grease and replace it with new KitchenAid grease, it is also recommended that you replace the gearbox gasket.

We are one of KitchenAid's largest service centers in the US, everything we sell is Genuine KitchenAid replacement parts.

Here is a link to the grease on our website: http://www.mendingshed.com/kagrease.html
And a link to the gearbox gasket: http://www.mendingshed.com/mixergasket.html

Also to aid you in the repair here is a link to the KitchenAid service manual for your mixer. this will show you how to take the mixer apart, replace the grease, and reassemble the mixer. http://lib.store.yahoo.net/lib/mendingshed/kitchenaid6qtservicemanual.pdf

Thank you,

Colleen
Customer Service
MendingShed.com
800-339-9297

Wipe the oil off and carry on. Over time the gearbox grease breaks down and oil separates from the grease solids. Eventually the gearbox will need to be repacked with new grease. Don't worry about a drip or two in a cake, it's food grade grease so harmless.

Your gearbox grease is breaking down, time to repack it with some new stuff.

Most likely you will need a new fuse gear, it is inside the gearbox.

Kitchenaid says to run the machine on 'high' long enough to heat the gearbox well and then turn the machine upside down and let it cool.

What happens is when you don't use your mixer a lot the grease in the gearbox will separate into oil and thicker grease. Warming it and turning it upside down is supposed to mix all the grease together again and allow it to flow to the top of the gearbox.

Give it a try, check back if you get no satisfaction and we'll get you started on changing your grease.

lp

Food grade grease is what Kitchen Aid put into the gearbox originally. They do supply it as a spare part if you cannot find it as a non Kitchen Aid part.

it sounds like the planetary has gotten loose and dropped down. Check out this parts list so you can see how it is put together.

http://shared.whirlpoolcorp.com/assets/pdfs/literature/Repair%20Part%20List%20-%208212057.pdf

Try pushing up on the shaft which holds the mixing attachments. It should not move more than 1/32 inch - if it does then something inside the gearhead is worn and you will have to take it apart. If the whole planetary moves up and down then something deeper in the gearbox is worn.

To take it apart lay it on its side and carefully pry the chrome ring off. Now drive out the pin that goes thru the planetary and the shaft. Now pull the whole planetary off its shaft. Remove the six screws underneath plus the other screws you can see from the bottom of the gearbox - there are 4 more. Now carefully pull the top half of the gearbox from the bottom half, which will expose the gears. Examine for worn parts and replace the necessary ones.

TRY REPLACING GREASE IN GEARBOX AND MAKE SURE YOUR FELT COVER IS IN PLACE (AND CLEAN) THAT SITS UNDER GEARBOX.
**** KENWOODCHEFUSEDMIXERSANDSPARES

With the machine unplugged, remove those two black screws on the side and pull out the motor brushes. Make sure the metal blocks on the ends of the springs are in good shape. These wear out and the screws are there to easily replace them. You can order new ones cheap from kitchenaid. If it's not those brushes then the problem could be in the gearbox and you can't fix it. Are you sure it's not a bent wire whip or mixing paddle banging against an improperly seated bowl?