Product review (1 stars): Not precise enough for OEM part
My wife's closed to 10 years old mixer started having the issue with loose planetary. I disassembled the gear box and identified a few gears worn out and the planetary shaft being loose from the base. I replaced the planetary with this one, every gear parts, and the lower bearing part so that I could recondition the mixer as her secondary mixer as we bought the "real" Pro Series to replace this mixer. Unfortunately, the replacement part didn't fix it because for some reason its center shaft is a bit too long so that the planetary still comes down as I ran the mixer with a mixing attachment. It is not as bad as the original issue but still bad enough to hit the bowl. I tried everything (probably reassembled it 10 times) to see if I'd made any mistake, but there was still about 1/12" or 1/6" gap, which caused the shaft to drop down. The issue looks like this video at 1 minute mark:

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I have spent enough time with trying to fix the mixer and the mixer is going into the garage today and will be sent to the proper disposal with my wife's approval. I am quite disappointed that OEM part didn't have the precision required. It almost wants me to buy the same, new, mixer and disassemble it see what it really looks like in new.

BTW, people, please buy the real "Pro Series" from KitchenAid. It costs more but with 5 year "full replacement" warranty, which renews itself  if you ever get a replacement while you are being covered, I think it is worth it (plus you get more powerful mixer). Our new "Pro Series" mixer actually got replaced in a year after the purchase because it started making a clicking noise - we were worried that the same could happen to the new mixer. My wife is very happy with the new mixer and the service provided by KitchenAid for "Pro Series".