Okay - I've had my 2006 IX for about 10 months now. I have 19K miles on it and about a week ago started hearing a BAD grind sound. I checked my rear brakes (as this is where is seemed to come from). I saw nothing odd - the wear markes were not even CLOSE to touching the rotors. TODAY - after going nuts trying to figure out what the heck...and RE-CHECKING the rear rotors...I spot THIS...



Soooo..I go buy some rear pads fast...remove the tires and start taking the brakes apart...then I get to the brake shim...this seems to be my problem...?



Looking at the above - you can see that the shim appears to be cut in half...is this NORMAL?? My pads wore unevenly...and as a result my rotor got cut into (as seen in my first pick). I'm puzzled because the shims all seem to be 'cut' perfectly... I'm not happy that this happened. As I mentioned my wear indicator was not even close to touching the rotor. I had NO way of knowing this was going to happen until it happened.



Bottom line - I replaced my rear brakes...got new shims - that appear to be COMPLETE and I no longer hear the grinding. I did NOT replace the rotor OR resurface it yet. However, I'm thinking about going to the dealer to see if they'll warranty it?

I just wanted to post this to see if anyone has had this happen or to let others know that it CAN happen.

Take it easy!

 

Brakes are a wear item and they wont warranty it because there is no way to tell how hard you drive the car. For all they know it is 19k miles on the track or abuse...just saying thats what they will think. Wouldnt even waste your gas to drive down there.

 

Yes, those shims are normal.

I didn't recall there being wear indicators on the rear pads, but it's been a while since I changed them.

I think they're shimmed like that to contact the leading edge of the pad to the rotor first, maybe to shed water or corrosion? or just for better stopping efficiency?

I can't see the rotor cut that you speak of but it's probably not something Mitsu will warranty.

19k seems fast for brake wear but my rears went out before my fronts did. I think I got 33k before the first brake change.

Good luck

 

The brake pad wore - only on the outer edge - because of the shim. That was why I posted this. The inner edge still had about 1/2 the pad material left on it. I thought that it wasn't normal, but based on responses I recieved on my local evo board, ti seems to be though. I agree- 19k was FAST. Bottom line - I replaced the pads, shims which were COMPLETE, full shims not half shims like the stock ones.

I posted this mainly because the replacement shims were complete not half like the stock ones. I thought something was broke. Thanks for the kind response!

 

Are your new pads factory replacements from Brembo? or another brand?

My replacement pads didn't come with shims.

I understand your concern with the edges not wearing evenly, I don't remember what my wear pattern was like but it wasn't something crazy enough to trigger a question of normalcy in my head.

Maybe there was some other issues going on with yours?

 

I had a similar experience, and wondered the same thing. Brakes starting with a slight grind at about 35K -- it was the rear only (on the passenger side). When I removed the pads, the outer pad had knife edged just like in this situation --- I just caught it a bit sooner. Anyway, I replaced both sides along with the OEM shims, and am now thinking I should see if the knife edge may be coming back.

Hmmmm. Maybe I'll check on that tomorrow.

 

I went down to Kragen and bought their replacement pads...which I normally HATE and REFUSE to use for front wheels (I've had high dusting issues). BUT I was in a situation that I needed to replace the pads. The new pads came with nice shims that covered the whole pad. I honestly feel the stock shims caused the pads to wear unevenly and subsequently dig into my rotors at only 19K miles. I've never had that happen so fast before. I come from mustang gt's / cobra and 2nd gen lightnings in my past and have never had the brakes (all with large rotor/pads) wear out like this (knife edge is perfect description).

 

I swear I TRIED to catch it sooner. I checked my brakes just a week ago and could find NO sign of this happening. Then boom...yesterday. lol At least you got 35k out of yours. I never expected the brakes to wear so quickly. AND as I mentioned when I checked the wear marker was not even CLOSE to the rotor (as it was the thick edge of the knife).

 

I think my rears went after 20K miles of street driving only. It's my daily driver. From the info I gathered on the forum, the rear pads wear first when there's a lot of easy braking due to the braking bias/abs system relying on the rears more than the front. Under heavy braking, the fronts get heavier use.

My shims were identical to yours and I didn't notice anything extraordinary in pad taper when I pulled the stock units out. Fronts went at about 40K.

 

Just replaced my rear pads today after 34K miles. It started out with a grinding noise. Removed it fast, got the rotors cut and replaced the pads. The original pads wore into the rotors so deep that after I had them cut, the rotors just barely have the minimum thickness left. Put them on, drove home, and now they're warped. Have to get new rotors.

It's weird how the rear pads go before the front pads.

 

I know this thread is a little old but I'd thought I would chime in so other people can see that yours in not a unique case. My rear driver side brake did exactly that at around 12k. I got the same exact "grooving" on the outer edge of the rotor and really uneven pad wear. I always check my pads but you cannot detect this kind of wear without taking the tire off.
I did not cut the rotor, though, and 8k miles later, my rotors have not warped. Im not sure why you chose to cut. There was plenty of life left on the rest of the rotor. Your pads would have formed to the groove anyway.
If the OP is still around, could you take pics of the new shim that you bought? I wonder how a shim could cause uneven pad wear? Perhaps some brake grease got caked in brake dust and caused the shim to lift. Then the piston was pushing only the shim rather applying equal pressure across the pad. I do find this hard to believe, tho, because there is usually constant pressure from the piston to the pad.
Ive always attributed the problem to the misalignment of the pad from the factory or a quality check issue from brembo. Time will tell.

 

where can i get new shims from. i only need the rears. i bought the project mu pads but one of my shims was destroyed. ( don't ask)!!!
anyone?

 

This exact thing happened to me 22k miles rears are toast. Passenger side had 0% left, drivers side had maybe 20% left.

I was worried until I found this thread. My shims looked just like the ones from the OP. I bought Duralast Gold (DG1001) to replace ... from the local Autozone. I'm not spending hundreds of dollars on freakin' brake pads.

 

I have this same issue........seemed to be only from the passenger side also. Loud grinding disc noise, very annoying when comming to a slow stop. Guess it time to replace the rear brakes now.