Broken Film Advance Lever - Pentax 6x7

The film advance lever on my Pentax 6x7 stopped working. It started by feeling strange on advance, almost like a grinding feeling. It finally stopped working altogether. I've since purchased a Pentax 67 and I'm hoping that it being newer will give me more time before it happens as well. I hear this is a common problem. Anyone experienced this and have a method for keeping them in shape? Does a typical CLA lube the internals of the lever? The diagram for this lever seems extremely complicated.