Drivers side rear locks up really easily when I hit the brakes.

Grabby for me was always a little leakage past the axle seals in an 8 3/4 .
But it's fun to have one rear wheel lock up and freak nearby drivers out.
Last time I had that situation going on I used it to tease people who pulled out in front of me, or whatever.... Perfectly safe, but sounds like you're going to hit them.
Fun until the snow flies.
No fun if the fronts do that.
They say ya can't wash the sticky grease off the brake shoes, but ya can.
May need to do a rear brake light drag/burn run to get the shoes clean again.