uneven disc wear on rear brakes

[pixelzombie]

The drivers side looks normal but the passenger side doesn't have as much wear.
It feels fine, but this needs to be addressed.
I'm assuming it's the issue is with the sliding pins?

 

[Sam4]

goo time!

 

[Dialcaliper]

That’s a bit odd rotor wear pattern. How new are the pads and rotors? Slots and holes will cause some initial strange wear but should even out. Are the pads worn evenly inside to outside?

Standard things to check:
- Slider Pins
- Nub engagement with inner piston notch (piston rotation)
- pad spring centered on caliper (not one end caught up in the center hole