99, 4.0, auto, 4x4, ranger ext cab

I changed the rear brake drums, shoes, all hardware, cylinders and brake cables. The right rear now shudders then locks up with moderate braking. When manually adjusting brakes it feels as if something is out of round. I tried 2 drums with same results. I did notice that the original right rear self adjuster pawl had a groove machined in it where it contacts the adjuster. I'm the original owner and I do remember the dealer saying they did something per a service bulletin to the rear brakes. This was about 9 years ago. I suspect they replaced the original right rear pawl with the slotted version. I suspect that's why there was minimal wear to the right rear shoes as they probably no longer self adjusted. I'm starting to think that a bunch of rangers got to dealers with bent right rear axle shafts and the fix was to makes the right rear brake non self adjusting to prevent lockup. My axel shaft doesn't look bent when rotated. I guess I'm just grabbing at straws. Any ideas or similar issues would be appreciated!