Kitchenaid K5SS stand mixer, making GRINDING noises... Please HELP!!!

[GREATPIES99]

I recently got a hobart kitchenaid K5SS mixer.

It was in perfect clean condition when I received it, ran nicely (no issues whatsoever, no grinding noises.)

However, I saw a yellow tint around the trim band (suspected it may have been oil) so i thought it might need a grease change. I opened it up and found that the grease looked almost brand new, i was shocked! So i  just cleaned up around the trim band with dry paper towels and put everything back together.

): This is where things begin to get sad... I started up my beautiful mixer and VNRINGRIOGNIROEN I hear this horrid grinding noise! 

I scour the internet for cures or causes and many say its the worm gear and that the teeth are damaged etc. I know this is not the case because 1. It was PERFECT before I opened it (never even USED it yet) and 2. I opened it back up and the gears are PERFECT as well!!! I checked all of the other gears and they too are perfect (no missing teeth, no metal flakes or deposits which is a sign of broken teeth)

Whats wrong with my mixer? I suspected that A. The brushes were not touching the armature B. I knocked something loose while hammering the groove pin out C. When I mated the top and bottom covers I did not make sure the gears meshed well.

 

So far I've checked the motor brushes (they were perf.)

I checked for anything loose inside of the mixer (i see nothing yet... at least)

And I've mated and checked that the gears have meshed for the third time now. 

WHAT DID I DO???????? PLEASE HELP ME 

[Hiroshi]

There are a slew of gears on these mixers... my suggestion would be to pull it apart again and as you expose gears, rotate them by hand to feel for friction.