Because of leaking, I ordered a replacement valve and rings from Kohler in order to rebuild my faucet (Forte, one handled). I got the oval piece off, used an Allen wrench to loosen the handle's set screw and removed the handle, then unscrewed the bonnet, unscrewed the retaining ring on the valve and removed the valve (which is falling apart), then had trouble sliding the faucet unit up and off (seemed to catch or be stuck on something) but found a guy to help me get it off (upper body strength is great! ). I thought it might be mineral deposits making the faucet hard to pull off but there aren't any. When I was removing the old rings I felt something metal and rough on the back of the unit that the rings fit onto. I put a mirror behind the faucet to look at it. It's tricky because it's close to the back splash. There is some round metal structure with some little round white plastic thing in the middle. The edges of the metal are REALLY rough. What is that round structure sticking out on the back and is it supposed to be all rough like that?? I can't find any explanation anywhere. I'm wondering if I should try to sand or smooth the jagged edges on that round thing.

Because of leaking, I ordered a replacement valve and rings from Kohler in order to rebuild my faucet (Forte, one handled). I got the oval piece off, used an Allen wrench to loosen the handle's set screw and removed the handle, then unscrewed the bonnet, unscrewed the retaining ring on the valve and removed the valve (which is falling apart), then had trouble sliding the faucet unit up and off (seemed to catch or be stuck on something) but found a guy to help me get it off (upper body strength is great!!). I thought it might be mineral deposits making the faucet hard to pull off but there aren't any. When I was removing the old rings I felt something metal and rough on the back of the unit that the rings fit onto. I put a mirror behind the faucet to look at it. It's tricky because it's close to the back splash. There is some round metal structure with some little round white plastic thing in the middle. The edges of the metal are REALLY rough. What is that round structure sticking out on the back and is it supposed to be all rough like that??? I can't find any explanation anywhere. I'm wondering if I should try to sand or smooth the jagged edges on that round thing.

I figured it out. It is 75878 -- Diverter Assembly which I guess diverts water to the side hand spray gadget. I don't know how it works but that is what it is. In the attachment it is the black circle thing with the white plastic in the middle.

I still can't figure out how to pull off the spout assembly when it is sticking and not lifting right off. It's supposed to slide right off.