Hi, I'm new at this so figure I'll just jump right in and be ignorant...

We have a kitchen sink faucet (American Standard I think) that seems to have a retaining nut under it that defies logic. I've replaced the faucet, drain, etc in the bathrooms and it was nothing like this. This kitchen sink faucet has been flopping around for a couple months because I can't figure out a way to fix it! Of course it's very hard to see anything up behind this sink but it seems to have a nut that is rectangular and cannot be turned to tighten it up and stabilize this faucet! It appears that this rectangular thing hits the sides of the sink well when I reach up behind it to try and tighten it down. At one point I thought that maybe there was a lower or inner nut (?) on the threaded tube coming down and that this rectangular piece was just another stabilizer piece of some kind that snugged up above the thightening nut. I know that there must be a way to do this that I'm just not aware of because the faucet could have never been installed otherwise! HELLLLLLLP!

Thanks,
AtlantaShooter

I usually leave tough ones like this to Tom. Maybe it got buried, and he didn't see it. My answer will at least bump it up to the top. I would start with some of my automotive tools, a drop light and a mirror. Get a good look at what you are seeing. From there, with the taper of the sink can you unscrew it, and replace it with a hex nut? Cut it off starting with a recip saw and finishing with a chisel? Remove the sink? Hope Tom has a better idea?

Basically you should be able to tighten the retainer nut by using a basin wrench. For examples of faucets look here, http://www.plumbinglessons.com/sup/kitfa.htm
Some faucets have strange ways of mounting but most of them are straight forward. If you can be specific about what you have it will help. I.E. 2 handle deck mount or single handle pull out, etc.