Rear end alignment on Mazda 3 SP

Has anyone had problems with rear tires constantly feathering on the inside? I have the 17" alloy wheels on my Mazda 3 and they came with Goodyear Eagle tires. After bringing it to the dealer for an alignment, I was told the negative rear camber is within Mazda specification range. They suggested I try going with a different brand tire that wasn't as soft as the Goodyears.  I've had to purchase 3 tires so far since 2005!
 
Any suggestions would be appreciated!  

Have you been rotating your tires every 5k miles?  Mine didn't have any abnormal wear that I noticed.  I replaced two of them at 22k due to tire damage and only wanting to buy tires in pairs, and I just bought another two at 30k.  I got yokohama yk520 tires.  They're cheaper than the goodyears, quieter, stick better, and have a 60k treadwear warranty.  Just to compare the treadwear rating on the RS-A's is 200.  The yokos are 520.    

Yes, I have experienced what you are questioning.   I do rotate my tires every 5K, and I was getting inside wear approximately equal to 1/32" more than the outside edge.  I have replaced the BadYear's w/Falkens  (tread wear rating 360.)
I have a suggestion:  Depnding on how brave you are, or skilled, raise the car up and using 2- 17mm wrenches, loosen up the camber bolts located on the inside lower rear control arms.  Mark where they are originally so you can return them to those spots if you are not happy w/the results.  Then carefully (here's where the bravery comes in) twist the bolt until you've move the contol arm in one full mark out from where it was, more if it seems necessary,... on both sides, then tighten the lock nut up to it.  This has the affect of shortening the lower control arm, or bringing the bottom of the wheel/tires assem in toward the middle of the car and more inline w/the top of the tire, or less spread out @ the bottom.

I did this last fall expecting to (finally) get my springs installed soon and have a proper alignment done anyway.  The springs are still in the shop.      But the handling allows for a bit more induced oversteer w/o being excessive, imo and my tires are wearing much more evenly now.

Virgin1...the only way to "adjust" the camber on the rear of a mazda3 is with longer Camber links (upper suspension link)  Not sure what you're adjusting, but it's not camber.
 
With my suspension at -1 degree camber in the rear, I'm getting about 42,000 miles out of a set of tires (they are more worn on the inside edge than the outside.)  I suggest something with a wear rating of 300 or higher....

There are camber adjustment bolt (cam-bolts) @ the inner point of contact for the lower rear control arms too.  The uppers are a replacement for the non-adfjustable factory ones and are for further adjustment @ the upper control link, as in after installing lowering springs or coilovers. 
All ya' gotta' do is look and you'll see 'em!
 
 

Yes I've had a similar problem on my UK spec Mazda 3 Sport.
I sent it for a 25K mile service to the dealer and asked that they check the rear whells/bearings because I was hearing a loud roadrumble.
When it returned they sdaid the problem was worn rear tyres! At 25K miles I might expect front tyres to be showing signs of wear but not the rear. Last car, an MG ZS, old design, had done 40K one 1 set of tyres.
I could not see any tyre wear on the rear. Took to a tyre depot - they confirmed that the tyres were worn on the inner edges - but not evenly worn, worn in patches. This explained the rumbling.
Back to the dealer to complain.
Initially tried to claim that Mazda do not warrent the adjustments beyond 12 months - car was 21 months old. Told him he could re-think that one (bit more colourful language than that). They took the car away for 3 hours to check it out on a jig. Came back with computer redouts saying it was within Mazda Spec but that thre had adjusted it to make it better!!!!
Dealer then said maybe it was bad tyres - well I bought the car from you, with tyres, faulty so replace them.
The compromise was that 1 had 4 tyres for the price of 3. They had to change the alloys as well due to corrosion so they got away light really.
I was not impresed with the dealer for returning the car to me with tyres incorrectly wearing and then insulting me with "don't warrent adjustments beyond 12months". Also not impressed with a modern car than has a rear axle ajustment.
Change of tyres cured the roadrumble - far more enjoyable motoring now. However, will be back to the dealer to get the wear checked in 6 months.
I think it's a good job I had not rotated the tyres - if I had I could not be sure whether the waer was cause on the front or the back.
 

thats sick (vigrin1)
i'll have to check that later

quote:

ORIGINAL: mgw
Also not impressed with a modern car than has a rear axle adjustment.

 
After having had many cars w/none, I think that's a very good thing.
All vehicles get out of adjustment after months or years of rough roads, pot holes, and geberal wear and tear.  And in the past, the aftermarket has come up w/quick "Band-Aid" style fixes for a lot of them.  Often cam-bolts or shims have had to be added in places they were never intended to be in order to bring a car back into specs.  The fact that adjustments are there for the inevitable is a very good thing.
 

I am experiencing this same problem.  I replaced the badyears after 30k with Cooper Zeon's and not I am experiencing bad road noise and bad wear on the inside edge after 10k with rotation after 5k.
 
I have had the alignment done and recently check by the dealer who is of no help.  They just said it was the tires. 
 
I can also see that the camber is out just by looking at the back end of the car.  I took the car back to the shop where I bought the tires and they tell me that by pulling down on the back end of the car they camber moves out further on the alignment maching indicating the springs are weak.  I am going to argue this point with the dealer and will let you know what they say.

You can visually see the negative camber designed in (-1 degree stock), you are correct, the camber does go more negative as the suspension compresses (also design intent), that is the main reason you need to install the camber links after a suspension drop to prevent even more excessive tire wear. 
 
It doesn't indicate the springs are weak at all, the shop you are going to is taking you for a ride, the suspension geometry requires that the tire go through the arc that it does during suspension travel.

sstlaure:  Believe it or not I can see the negative camber on this car.  It measured at -2.3 and -1.9, but I think it is far worse than what it measured.
 
The car is stock and I have not modified the suspension at all.  So with this being the case what would cause my tires to wear so unevenly?  I guess I need to add a camber kit to a car under warrenty see as how the dealer will not do anything to correct the problem other than tell me it is the tires that are the problem.
 
Any suggestions would help greatly!

quote:

ORIGINAL: nybdr529

sstlaure:  Believe it or not I can see the negative camber on this car.  It measured at -2.3 and -1.9, but I think it is far worse than what it measured.

The car is stock and I have not modified the suspension at all.  So with this being the case what would cause my tires to wear so unevenly?  I guess I need to add a camber kit to a car under warrenty see as how the dealer will not do anything to correct the problem other than tell me it is the tires that are the problem.

Any suggestions would help greatly!

I've only had my car since 5/12/07 and I've noticed this. The car was in the garage and I was down on the sidewalk. The rear tires are not straight up and down, the tops lean in some. The first thing I thought about when I saw this was uneven tire wear. I've only got 600 miles on the car but on my first service visit, I will address this to the service writer. That way it's noted in my first service call in case I have tire problems later. Also about the GoodYear RS-A Run Flat tires that came on my 3, the tire wear rating is only 260. I figure I'll be lucky to get 20K miles out of them, that's a very low tire wear rating and at $268 each, I won't get them again.
Jim

I just had my tires rotated at 5k and will continue to do so every 5k in an effort to maximize tire life.  The camber is for handling, as I'm sure most of you already know, so I'm not surprised that the MS3 has some camber.  If the tires are not directional, have them broken down and mounted the opposite way on the rim at some point.  The added life may be worth the cost of a mount and balance.  Discount Tire will rotate for free.

quote:

ORIGINAL: blackdiamond
I just had my tires rotated at 5k and will continue to do so every 5k in an effort to maximize tire life.  The camber is for handling, as I'm sure most of you already know, so I'm not surprised that the MS3 has some camber.  If the tires are not directional, have them broken down and mounted the opposite way on the rim at some point.  The added life may be worth the cost of a mount and balance.  Discount Tire will rotate for free.

 
i believe it's more in the interest of safety... Mazda's.  I took out quite a bit of the neg camber and now the car turns in better than before.  too much neg in the rear of a FWD car causes it to understeer much more, and I'm sure Mazda doesn't want all kinds of lawsuits from those ppl that can't handle it (re: drive.)