Janet Bradshaw it is possible that the plastic drive pinion gear is slipping. The plastic version of the gear splits frequently and it will run under no load but once some torque is required, like when it needs to mix stuff, it will slip. We will need to see the gears as well as the gear housing since there are some rivets that create a weak spot and can separate the case.
THis guide Disassembling Kenwood Chef A701A Gearbox and Orbital Mixer assembly (could be a different model than yours) shows you an approximation of what could be involved.
Adding images to an existing question
The metal part is actually what screws on the gear shaft for your planetary gearbox. If there would be some sort of mechanical issue in the gearbox and the motor would continue to try and drive the big plastic wheel, the increased resistance would cause the clutch wheels (red arrows) to rotate inside the plastic gear but would not drive the metal bar that connects the clutch wheels to the gear shaft. Looking at the "debris" it doesn't look like it does that. The debris would not be there. Run the mixer with the cover off and see if the metal moves when no load is applied. After that mix something heavy and see if it then stops the metal part from moving and the two clutch wheels move roll on the arm within the plastic gear. The metal arm should not be moving.
Found something. The A902 seems to have the same gearbox as your KM 201
from here
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Janet Bradshaw what model is your Kenwood Chef? Is the speed normal when it runs empty? Any noise coming from the transmission? This could be a motor issue but it can also be a transmission issue. Time to look at the gear etc. To see what's going on.
crwdns2934271:0crwdnd2934271:0 oldturkey03 crwdne2934271:0
Km201
Yes it’s seems ok when empty. You have just reminded me. That’s why I took it for service and repair. The motor stopped and was replaced.
How do I get to see the gears?
crwdns2934271:0crwdnd2934271:0 Janet Bradshaw crwdne2934271:0
@Janet Bradshaw You should read through the guide that @oldturkey03 posted. Yes, it’s a different model but still.
crwdns2934271:0crwdnd2934271:0 Geir Ove Andersen crwdne2934271:0
I’ve added more pictures. Not sure how to get to the motor. Tried to unscrew the three screws but nothing moved. No gear in cover as you suggested
crwdns2934271:0crwdnd2934271:0 Janet Bradshaw crwdne2934271:0
@Janet Bradshaw Excellent pictures! Everything looks alright, except one thing; In the third last picture, you can see a lot of dust (I'm assuming it's not flour that magically got in there), but it's wear from the offwhite (and small) discs that should touch the inside of the rim of the nylon gear.
I can't find that part alone, for replacement, except one "refurbished" one on eBay. However, there are complete gearboxes available for the KM201, for around $100 US
https://www.buyspares.com/chef-range/km2...
Note: I have never purchased from that site, so I have no experience with it!
crwdns2934271:0crwdnd2934271:0 Geir Ove Andersen crwdne2934271:0
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