So now that I've duked it out with my shower diverter and replaced it, I replaced it with a "Danco" diverter. The store where I got it, and I trust them for the most part, implied that getting the manufacturer's replacement is not a problem, but not necessary for something as common as a Price Pfister 3221 shower diverter.
I installed it, very simple, replaced the seat, very simple but time consuming with all those stupid faucet handles in my way, but when I use the shower the tub spout doesn't quite seal.
The tub seals nicely, that is when using the tub spout no water spills out of the shower head like it used to. Unfortunately when using the shower, water still comes out of the spout - and when switching back to the tub the pipes make a loud gurgling noise.
In the off-chance it was the shower head that was clogged I took the head off and ran the shower, the problem still existed, although I did pull a heck of a lot of rust out of the shower head.
So my question is, is the tub spout supposed to leak while the shower is going? I thought I saw a mention of vacuum lock here. If it is supposed to leak, how much. In my case you could fill a large glass with water fairly quickly. The new diverter does seem to leak a bit around the stem o-ring, but doesn't leak at all so far where the diverter screws into the shower fixture.
So I guess my question is, a) does the replacement set matter b) Is leakage from the tub spout normal