tub/shower diverter problem

I was replacing the washers on my tub valves today and after putting them back together, the valve that diverts the flow to the shower head doesn't seem to be working correctly. (I have three knobs all in a row.... hot, shower/tub, and cold). It did this before I replaced the washers, but it seems to be a little worse now...

When the valve is in the "tub" position, it fills normally, but when it is in the "shower" position, water comes out of both the faucet and the shower head.

Any tips? Does the valve need to be replaced? Thanks for the help.

Sorry we overlooked your question.

This is probably a simple fix. Most diverter stems have a rubber washer at the end, similar to the hot/cold stems, but also have another, often a hard white nylon washer, BEHIND the nose of the stem. This washer is the one that stops water from going down to the spout when using the shower. They ofter break. Make sure to look inside the valve body with a flashlight for any broken pieces of the old washer.
All the pieces can be replaced, but it is simple and inexpensive to just buy a complete diverter stem. Take the old one with you to the store to get the right one.