I tried the deglazing with sandpaper, no change.
I fixed the problem, I tore the wheel apart and laced in another hub shell.
Its a shame because the hub I took out looks almost brand new.
The one I put in was out of an odd wheel I had here from a 26x1 3/8" bike.
I swapped all the inner parts over and its quite and don't kickback.
The funny thing is I can't find a thing wrong with the old hub, it just wouldn't work right.
I took a late night ride up and down that hill 5 times and not hardly a sound and it stops smooth like it should. The hub gets
warm but not sizzling hot. Same grease, same internals, just a new shell.
Here's some pics of the hub shell I removed, maybe someone can spot something? I went so far as using a dial indicator and the inner barrel is dead round, its shiny smooth with no gouges or rust, there's no grooves, no bumps, nothing. It looks brand new.
I'm starting to think maybe its why this bike never saw much use.
It took me 20 minutes to un-build both wheels, 10 minutes to clean up the second hub and swap all the guts over, and two hours to clean and polish all the spokes so the wheel looks brand new again.
It took me a half hour to dig out my old Hozan truing stand that was buried under a two years worth of junk on the work bench. Then another hour trying to find the right axle adapters to fit the coaster brake axle.
I'm glad it was quiet, it was almost 1am by the time I did the first test stop on the hill down the road. The big plus is there's no traffic around at that time.