Thank you for this thread posting.
This thread gave me some guidance on how to deal with Kohler. I experienced the same treatment from Kohler as you guys had posted. As posted, they wanted to charge ~$50 for the anchor kit but insisted I only need the anchor nuts. They mailed 2x anchor nuts (molly-type) part # 85040 and 2x screws part # 84741 which took 30days; I called them back after one week and was told the anchor nut were back-ordered.
Here is the picture of the anchor nut, Kohler PN 85040
Timeline: seat cover broke last week of April. Called my local Kohler Distributor and ordered a seat cover and delivered on May 2. I realized that the new seat cover did not have the correct fastener. So the wifey called and yelled at Kohler so they sent another incorrect hardware set with plastic cone-shaped wing nuts. In the meantime I scoured the WWW and found this thread. I called Kohler May 28 to demand the anchor nuts. Received the correct anchor nuts and screws July2! July 4th new seat cover installed.
a) 2x anchor (molly-type) nuts part # 85040 from Kohler
b) 2x 1/4-20x1.5inch screws part # 84741 from Kohler
c) Bought from local hardware store: 1x 1/4-20x1.25in HEX top bolt and several flat washers ~$1.00.
( For nuts/bolts and specialty hardware, I always waste time at HD or Lowes so I go to my favorite neighborhood hardware store. Thank God I have one in my neighborhood. In the Silicon Valley we have one of their store there http://www.olander.com/ )
1)Extract the old seat cover bolts by cutting them off with a hacksaw. Use duck tape to protect the procelain. The lower portion of the bolts will drop into the recess of the toilet that is not part of the water way.
2)Be careful not to damage the porcelain and drill out the remaining part of the old anchor (hard plastic in my case).
3) Insert the anchor nut and gently tapped them into the holes with the butt handle of a hammer.
4) Take the 1/4-20 x 1.25 HEX top bolt and wrap it with teflon tape just in case you want to remove it again in the future. Insert the flat washers onto the bolt. Place the bolt into the anchor nut. The shoulder of the bolt maybe about 0.5inch above the anchor nut
5) Using the socket/rachet, start compressing the anchor (molly-type) nut. As you turn the rachet, the anchor may turn a bit but make sure it stays flush onto the porcelain. The rachet turns should be smooth and with consistent torque until you are to the compression point. Remove the 1/4-20 x 1.25 HEX bolt.
NOTE: if you need to hold the anchor nut from spinning, you can use 1/2in or 13mm thin open-wrench.[/I][/I]
6) Do similar steps with the second anchor nut.
7) Install the new seat cover.....a happy wife is a happy life :-)