Cannot find a solution to poorly performing rear brakes

It took me 6-7 tries to get the parking brake adjusted to the sweet spot where it will hold the truck in "D" and not drag. Almost drained the battery lol.

 

Do this:

From the service manual:

ADJUST REAR DRUM BRAKE SHOE CLEARANCE

(a) Provisionally install the hub nuts.

(b) Remove the hole plug, and turn the adjuster to expand the shoe until the drum locks.

(c) Using a screwdriver, release the adjuster 15 notches.

(d) Install the hole plug.

You will find this makes a lot of difference.