What kind of pocket watch? Positive or negative setting? If you push down on the crown while winding, does that work?

 

It's a negative setting.. I think, because the stem and crown are part of the case. Might I have accidentally done something to the sleeve?

 

Once upon a time I serviced a watch and found a small square of metal laying on the bench after I disassembled the movement. I couldn't figure out what the deal with it was until I recased the watch and found that it wouldn't go into the winding position. The small square of metal had been put into the square in the winding arbor to make up for a stem that was too short and a sleeve that was screwed all the way in.

 

Most likely you need to adjust the sleeve. You need a sleeve wrench to do this correctly-these are no longer made(AFAIK) but are readily available from used tool dealers or found on Ebay. Just be sure that you're not buying one with broken tips.

In any case, to use one you need to first remove the movement from the case. Then, remove the crown from the stem. I use a pair of smooth jawed pliers to grab the square of the stem, but a standard pair of pliers with a small piece of cloth or leather in the laws will do in a pinch. In any case, once you've grabbed the stem, just unscrew the crown.

If you look down the pendant, you will see the sleeve-it usually has either two or four notches spaced around the perimeter. Find the tip of the sleeve wrench that fits best, and then turn the sleeve clockwise. A small adjustment here usually make a big difference-I'd start with a half or even quarter turn.

Then, put the whole mess back together. If you guessed wrong on the amount to adjust it(which you probably did-I've been doing this for several years and still usually get it wrong the first time), take the whole mess back apart and make another adjustment. If you find that the watch will wind but not set, you need to back the sleeve back out. Keep messing with it until it works correctly.

If you find that the sleeve keeps backing out, you may need a drop of locktite.

One last thing-the sleeve has four spring loaded fingers that cause the stem to "snap" in and out. Sometimes one or more of these break. The sleeve will usually work okay with one broken, but you can have issues if more than one is broken. In that case, the only real solution is to replace it. You can't call up a material house anymore and order a replacement by the make and size of the case-your best bet to find a replacement is to find a watchmaker who has a couple hundred of them and sort through them until you find the correct one. Either that, or find your own stash of a couple hundred sleeves