Please tell me where i can buy the replacement

Hi, UIDA_2000, Sorry to hear about your gear issues. The inspection and troubleshooting of your mixer’s transmission is a DITY capability, particularly if your mixer is out of warranty. Just be sure to have the correct Part List manual around when you start to disassemble your mixer. If you're lacking one, you can download it from the KA website (http://www.kitchenaid.com/flash.cmd?/#/page/home).
Click on Customer Care>Locate Manuals& Guides> and enter the 6 character model number, in your case KP2671, and select one of the files that appear under Parts List file. Turn to pages 4 & 5, titled ‘Case, Gearing & Planetary Unit, for the disassembly, troubleshooting, and reassembly of your mixer, along with all the parts.
You will have to remove the transmission gear case cover to access all the gears. Then you will have to remove all the grease to inspect which gear has failed. It may be messy but gratifying. Once apart you can check for any other unseemly wear and tear on the gears, etc. You may find that it's just one particular gear that’s stripped. (The bevel gear Illus. No. 21, on my wife’s machine lost a tooth and jammed, but I was able to repair it quite easily.) Besides needing a replacement gear and grease you might consider replacing the gasket, too. You should use a food-grade grease that you can order online (although I’ve seen automotive bearing grease used too – your call).
As far as parts go, here are four potential vendors in no particular order: RepairClinic.com; mendingshed.com; searspartsdirect.com; partstore.com. Prices for the same part may vary widely between vendors, so do your comparison shopping.
Here’s a link to an excellent site for disassembling/fixing your KA Mixer. Although it’s a different model, the principles are the same: http://www.neilcrockett.com/mixer.htm and another link to a site that details the disassembly and replacement of mixer’s grease, which might be helpful, too. http://www.foodonthefood.com/food_on_the_food/2009/04/how-to-repair-a-kitchenaid-mixer-yourself.htmltl
If you feel troubleshooting and repairing is beyond your capability, then I would seek out a local small appliance repair shop in your area. KA Customer Care can give you names of local KA authorized repair shops in your area, but you can also do an online search to supplement what KA may provide you. Call to explain your circumstances and find out their hourly rate and get an estimate of what they think it would cost to repair your mixer. Also, always obtain three or more estimates – do some comparison shopping.
Good luck and have fun. I hope this helps. Howard, Burke, VA
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