Our shower has a Kohler valve with a push button diverter. The part number for the valve if you were to buy it today is either 11748-K-NA or K-11748-KS-NA. The place was built in 2010 and I'm not sure how far back those part numbers go.

The diverter is stuck in the "in" position which sends the water to the shower head. Calling Kohler support, they suggested that the diverter is faulty and it's probably not that the push button on the valve trim that's jammed up. I considered wrapping the push button with masking tape and pulling on it with some channel locks, but I'm afraid of it then getting stuck in the position that sends water to the spout.

I guess my first issue is that I don't know if I need the pre 2009 diverter kit (Kohler # 89773) or the one the later one (Kohler # 1081410) but it will probably become obvious when I remove the valve trim.

I can't find any instructions online as to how these diverters are replaced. It looks like they are threaded, is it a simple case of unscrew the old one and screw in the new replacement? I see some o-rings, but is there anything else required when putting in the new one to prevent leaks?

[www.us.kohler.com]
I got this from kohler's website, it looks like the whole diverter unscrews. It is a good idea to lubricate the O-rings with faucet grease before installing the diverter. I would try taking the old diverter out and soaking it in white vinegar overnight as my first guess is calcium buildup. It may be the spring has broken or become dislodged somehow. I looked at the parts diagram [www.us.kohler.com] and it looks like the spring, or the E-ring (retaining clip) that it pushes against could be your problem if it isn't just calcium buildup causing it to bind.