These guys are right, toe worn rear tires. The shop you took it to either doesn't know how to do rear alignments or does know and is too lazy. Either way, find a better alignment guy. This is a common issue with these cars from what I hear, but not at all a difficult fix for someone who knows what they're doing.

 

My rear tires wear terrible and also growl like a bad wheel bearing. I actually tore it down expecting a bad wheel bearing. I am trying to find a place to align it and straighten it out but don't know where to bring it...

 

where ever you end up going; tell the service writer about the first alignment fail. Book it in when there best alignment tech can address it...no one else. Make sure you request the alignment print out to verify the final adjustments. Post the print out here. I'd like to see it.

 

That's good if you like it.

 

Another quality post.

 

Ok I found a alignment shop with computer read out. Toe was off on both back tires. Cam bolts had to be installed also to get it aligned. Cam bolts was also added on front end to get it right. I have had problem with this since new. Complained to chevy about noise in rear of car and it eating tires on inside. Sad you have to buy extra parts to align car. All noise in rear end is gone since they aligned it. Car is going on six years. What a difference to drive it and not have all that rumbling noise in rear.

 

post your alignment numbers.

You don't need eccentric bolts to adjust toe on this car. The rear toe is adjusted by turning the rear link adjustment sleeve. I do alignments on these cars every day. No addditional parts are needed for toe adjustment for this car EVER.

even with correct toe settings, the toe worn tires will still be noisy until replaced with new tires.

Factory alignment warranty on a new car is only for the first 12 000km.

 

Tech 2... I see that you did an edit 10/12 My concern is the alignment/tire wear on my 2008 Impala. I did a test drive from Joplin Mo - Springfield Mo, round trip approx 125 miles. I was aware of the 'call-back', but only for police vehicles. When I arrived in Springfield the first alignment check was to place my hand on the tire surface and pull over the tire. That sharp saw tooth feather edge was not there. I purchased the Impala from a one owner with high mileage. Tires have been rotated with no signs of wear. This rear design is new to this wrench, but if does not show and or appear to have signs of wear with highmileage, I will assume that my alignment is with-in specs. I will return to CF ....I have some more bonding to complete with my 'new' Impala. I want to know more about the flexfuel 3.5 and the tranny with the DextronVI fluid. Found a new asset in the cargo back seat space. The bench seat pulls out and the back folds down for more cargo space.

 

your alignment is probably good then.

Did not know the rear bench seat pulled up. Will have to watch for that.

flex fuels cars get no use as intended where I live. in canada as we only have 10%max ethanol blends in our filling stations. Is it a California thing? google what happens to non-flex fuel cars when 15% or higher ethanol fuels are put in the tank.

 

The cargo space is from the trunk to the back seat area, when the back seats lay down.
Flex fuel will not be an option. I will however add Marvel Mystery Oil {4-6 oz} to gasoline. MMO offers many assets. Upper cylinder lube is critical. Reduced Carbon build-up in combustion chamber.