A shower and tub diverter repair is for three-handle shower/tub faucets that use the center handle to divert water from the tub spout to the showerhead. The center assembly consists of a handle for the shower diverter, an escutcheon (chrome trim under handle), a stem, packing nut, and the housing.
The knob that diverts water from running into the tub versus the showerhead was leaking. The stem was changed and now I have a problem when I want to take a shower. Half of the water comes out of the tub spout. We are ankle deep in water when taking a shower.
Once you remove the handle and escutcheon, you should see a small nut, the packing nut, and a larger nut just below it. The larger nut is the housing that will have to be removed to accomplish this repair. If the packing nut is missing, look in the escutcheon because it often is stuck in there. Try to remove it from the escutcheon, prepare yourself because this can be a battle. If you can remove it from the escutcheon, screw it back into the housing to prevent crushing it during removal.
Another way to prevent crushing the housing is to get a set of diverter sockets. They are deep and stackable, and they make removing shower stems easier. They are available at most hardware and plumbing stores for a small deposit.
You do not have to turn off the water when working on a three-valve diverter.
Turn the diverter stem so it is between tub and shower modes. Take the tub socket and unscrew the housing to remove the diverter assembly. It is a standard threading, counter clockwise to remove. If the housing will not pull out, it is because the lower washer had swelled. You will have to pull and rotate to remove the housing.
Then take it to a hardware or plumbing store to get the appropriate washers. Most diverters have two seals on the housing. The upper washer seals the housing to the body of the faucet, and the lower washer seals between the tub and the shower ports. If that lower washer is missing or miss-aligned, the shower will feed both the tub and the shower at once, which is your problem.
Sometimes the diverter washer can be tricky to get situated during the install.