My shower stem has a slotted part behind the seat. I was told to have this part up to keep the stem from leaking. I drew a line down the stem so I would know it was upright so it would not leak when the water is on. But when I put it in and tighten it up that part is lineed up so it leaks. What can I do to keep it lined up after I tighten it up?
Viper3

Can you take a picture, please? I can't for the life of me figure out what your talking about.