2 knob shower faucet leaks when water is on

[radioheadonic]

Hey there,
It seems that the stem of the hot water of my shower is not centered and with time whatever fix I try fails and water starts leaking when faucet is on again. Tried graphite packing tape and also I believe a bonnet packing. I cannot replace the whole faucet at this time so I am looking for some help. Thanks

 

[havasu]

Do you know the brand? Have you tried to replace the entire stem? Do you have a good plumbing store near you?