Shower Diverter help

[Dan M]

The diverter in my shower/tub only diverts about half the water to the shower. The rest runs through the tub spout. The diverter is the turn handle/faucet-type with separate faucets for hot and cold water. In other words there are three identical faucets, the center one is the diverter. it dates from the early 1980's.
Can someone give me basic directions on how to fix it or show me a web page that has directions?
Thanks - Dan

[Basement_Lurker]

give this a read:

http://www.stemdoctor.com/stemdrcom/...5-68c1335aa569