When I turn on the shower, water is not making it up to the shower head, rather spraying out from behind the knobs to turn the shower on? Is it just bad gaskets? How should I repair.

Best bet is to post back with the brand and model. Tom will give you the right fix. While waiting for his answer, take the knobs off, the screw may be under a cap you pry off. There may be some nuts there. Tighten them up a little and see if it helps.

Thanks. I'll try that

If you lift your diverter knob on spout and water comes out anywhere other than the showerhead - you have a break or terrible leak. If this is a 3 handled valve it sounds like diverter is leaking.odd you do not have water showing up elsewhere... the make and model, and approx. age of faucet would be helpful.