Need help repairing leaking Gerber faucet

Hi there. New to forum and this is my first post. The faucet in one of my bathtubs is leaking. It is a 3 handle Gerber faucet and it must be at least 20 years old if not older. The house is 40 years old. I've removed the handles to the hot and cold valves and now I see two things that are hex shaped. The first one is 3/4" and the stem goes directly into this. Then this one screws into a larger piece that is hex shaped (maybe 1") and it screws into the main body. Which one do I need to remove to repair the faucet? Also, does Home Depot or Lowes carry repair kits for Gerber?

Secondly, I can't remove the handle for the diverter valve. I removed the screw like the hot/cold valve handles but it won't budge. Since this is an old faucet i was going to replace the handles while I have it apart. ANy suggestions on removing the handle?

Thanks,
rob

An inexpensive handle puller ( looks like a gear puller if you a familiar with mechanics tools) is available.


The outer-most nut you see is a packing nut. To remove the stem for repair or replacement, you need to get a "shower stem socket" which fits down over the inner, larger hex. These tools are also inexpensive and readily available.

The stock at a Depot or Lowes varies regionally. If Gerber is a brand widely used by builders in your area, they might have it. Here in So. Cal. it is all Price Pfister, with a spattering of Delta and Moen It is a common brand, so any plumbing supply will have it.

Thanks

Ok, so I need to remove the outermost (largest) nut, right? I will look for the tools. Are "shower stem sockets" the same size? Is there an industry standard size for this? Thanks for responding so quickly.