Strange OEM rear pad wear

[MS6_OH]

I just changed the rear pads with oem pads for a quick fix. When I took the pads off, they had very uneven wear from the passenger side to driver side. I did a search and found one post by someone else mentioning the passenger side rear pads wearing quickly, but he was looking for other pad options rather than a reason.

Wondering if I have a caliper issue or anything else that could cause this. Car is an 06 MazdaSpeed6 with 33k. These were the factory pads, here's some pics to compare.

 

[MS6_OH]

Few views in here but no replies. Now that I have the new pads in, I can hear a slight drag on the rotor at higher speeds. I don't think the caliper is releasing properly so I'm going to have the dealer check it out in the next week or so.

 

[Blendercloud]

I don't remember if the parking brake actuates both the rear passenger and the rear driver calipers or just one of them. I was having a similar problem when the car was brand new.

I always park in neutral with the parking brake on and when I first got the car (with 16k miles on it) the rear caliper would hang up on it and you could feel the car jar as I would back out of my covered parking every morning. I pulled the wheels off to change the pads about 1,000 miles later and found a bit of uneven wear. Mind you, I don't remember which side was worse as that was almost a year ago. I checked for travel and play in the pistons and found none. I put it all back together and have never had a problem since.

 

[solidtrance]

I don't remember if the parking brake actuates both the rear passenger and the rear driver calipers or just one of them. I was having a similar problem when the car was brand new.

I always park in neutral with the parking brake on and when I first got the car (with 16k miles on it) the rear caliper would hang up on it and you could feel the car jar as I would back out of my covered parking every morning.

Pretty sure its both. I have the same experience and the rust it produces is visable on both calipers.

 

[Auto-Xer]

I just did brakes on 2007 6i--55K. Right rear was grinding--inner pad was gone, outer was maybe 25-30% left. Left rear was also more worn on indside pad--but not as bad right rear inside pad.