I recently installed Akebono pads on my Toyota Sienna.
The shims on the Akebono pads are already installed.....integral to the pad as show in this picture
I have read some posts that the pads that you get from the TOYOTA dealer are coming this way also.
I also bought a "disk brake hardware kit" for my vehicle.....the only thing in the kit that I needed was new slidder "clips"
Each of the 4 clips is different on each side (4 different clips for each side of the vehicle).
You can see the clips installed in these 2 pictures of the passenger side bracket.
You will put some lubricatnt onto these clips as this is what the pad rides on.
Note how the pads seat into the clips.....and will slide on these clips.
Also note that the little tab that sticks out on the clips point AWAY from the rotor.
I cleaned and re-lubed the slider pins. I used "Sil-Glyde" lubricant.
If the pins are worn, you can buy new ones....They are NOT part of the "disk brake hardware kit", you have to purchase them separately. On some sites, I had to look under "caliper bolt" to find the slider pin.
The rubber boot for the caliper slider pin is also sold separately.
One note that I read, when you install the greased slider pins, don't push all the air out such that the slider pin is sucked all the way to 1 side.....you want it kind of not pushing or pulling the caliper to one side.
I don't know if this is important over time or not....just something that I read.
Also. you want to lubricate the caliper piston to shim (back of pad)contact point as well as the caliper bracket to pad shim contact point.
You want enough lubricant to do the job, but not so much that is will squish out and get onto the rotor or pad friction surfaces.
On a 2011, the caliper pins and the slidder clips should still be fine....if they are not...then that would be something that the dealership should fix for free.
The slidder pins, and even the clips were fine on my 8 year old Sienna....but I installed new clips anyhow.
The pads had been replaced at a shop 1 time before I got the vehicle.....single shim (though the repair manual shows 2) and I just put the pads in as they came out of the box. My brakes were quite before....and are still quiet.
Now, rear DRUM brakes.......for the 2003 Sienna, there was a TSB out for sqweal sound that was solved UNDER WARANTY for free if a customer brought the vehicle in......the solution was to go to a different, NON RIBBED (smooth around the outside) brake drum that eliminated the harmonic that could happen and cause the noise.