Do C6s tend to lose their alignments over time or mileage?

The reason I ask is my 06 Z06 has some pretty extreme wear on the outside edge of the rear tires. They are just about to the wear bars on the outside and nearly full tread on the inside. I was hoping this was a simple case of a bad alignment from the factory but I'd like to know if this is something I'm going to have to keep an especially close eye on as time goes by.

With 18k miles (bought at 15k in November), the dealer said GM is probably not going to cover an alignment (even with my B2B warranty) so it will probably be on me. Plus the cost of the replacing the nearly destroyed tires very soon.

Thanks!

 

Been awhile since my first alignment, but I've always heard people on this forum complain about the factory alignment. Some seem to find their's all over the place while others seem to be "acceptable".

I recently got mine done again within a very short period as it seemed to tweak ever so slightly which was odd. The shop I use ensures every bolt is torq properly and they primarily do track cars so they are the best of the best locally. Not sure if this was a fluke or the norm for hard driven cars. My DD car alignment stays pretty dead on consistently oddly enough.

 

They lose their alignment as you crash into great big bumps in the road, but they have to be pretty big. I strongly suspect you either ran into something, or the alignment was no good to begin with, or both.

These cars can be aligned "within spec" and still eat tires. You'll need to find the tire shop in your area that knows what they're doing. These alignment specs produce even tire wear: http://forums.corvetteforum.com/1565502174-post14.html

Edit: I see you've got a Z06, the specs quoted above are for a narrow-body C6.

 

Find a "good" local alignment shop with modern equipment and knows how to do C6's. You can ask for shop recommendations in your Regional Forum. Good luck.

 

The front suspension arms are also known to extrude their bushings. Was already a problem in the C5.

 

fwiw, I've been told by a Corvette repair shop that they don't seem to hold an alignment, mine as well as others that they service being the examples. that said, there's no such thing as an alignment for X months/years, or Y amount of miles. just doesn't go that way.

as one posted above, one bump and it doesn't have to be that bone-crushing severe, hit the right way at the right speed and that alignment done yesterday can be slightly off. or it could be a curb, railroad track, etc. there are no givens to how long, either miles or time, an alignment will last or how much it will go out.

the best you can do if you care about your tire life is to get one every so often. for some that might mean once a year; for others, whenever they think about it which is usually when they replace their tires (sometimes prematurely).

 

Watch out for those metal plates in the road during construction as well. Currently on the state hwy near my house they have a "bump" where the new asphalt is a good bit taller than the current pavement. That thing beat me up in both my cars so now I've noticed many people slowing to a crawl to ease the jar it produces. They've tried smoothing it out but they must be rookies because they only make it worst.


I'm one who gets my alignment checked once a year usually. Rather spend $75 for a "check" than unecessary tire cost.

 

Interesting that they can get out of align that easily. In the 80k miles I've driven my C4 the only alignments I needed were due to mods I made or alignment tech mistakes (improper torque... twice). This car was also daily driven over some very bad roads.

I guess I'll have to keep a close eye out in the future.

 

Yes, I would, and I do.

 

One of the first things I do when I buy a new or used car/truck is have it aligned. I used to do alignments for a living. As some one said the specs are quite wide but the center of the spec is what we used to call the desired setting. In most cases this will give the best tire wear and drive straight. I am going from memory but I think the desired camber for my 08 base coupe is around -.42 Mine was right at -.4 when I put new tires on 7K miles ago. The wear looks very good. I think the suspension looks real good on my car. They have to be half way tough to hold up under some of you that track your cars. If not you would have them on the alignment machine on a regular basis. Later! Frank

 

See a lot of Z06s with this type of tire wear (mine included). I suspect the factory may put in a little too much toe in. The alignment specs for the rear wheels call for more negative camber than the front wheels but there is still a lot of outside wear. The C5s and I think the base C6s don't have this issue so I suspect it is the tire width. I went through a set of brand new GYs in 3K miles with lots of tread on the inside and cords on the outside. I purchased some low mile GYs from a forum member and noticed the same wear pattern starting on them so I currently have 4 sets of rear tires with all showing the same wear pattern. I have about -1.5 camber in the rear and still got this much outside edge wear so I reduced the toe in to 1/32 with the set of used tires I purchased and they seem to be holding their own although still have the original wear pattern.

If you aren't getting any other symptoms like dog walking or a twitchyness in the rear the alignment probably hasn't changed. However, it doesn't take much for it to change if the person for tightening the cam bolts on the LCAs doesn't do their job correctly. Had this happen after a shop did an alignment on my C5Z. After going to the track and really getting some wild handling I noticed the left rear tire was toed in about an inch and the right rear tire was toed out about a half inch so toe was into the next county and thrust angle was way off. Had to take it back and have the guy re-align the rear and then make sure he tightened the bolts.

Bill

 

Alignment won't change unless something - like a loose bolt or a big hit changes it. I mark the bolts after an alignment and check the marks periodicly.

 

First, thanks for the info everybody!

I got the car back from the dealer with a printout of the before/after specs. Everything is within the (huge) range except for the left rear camber. Nothing is spot-on, though.

The spec appears to be -1.00 +/- and the closest they could get was -0.13. They didn't see any damage or anything that jumped out as an issue. Does anyone have an idea what could be preventing this one area from moving where it needs to go?

I hit up the local SCCA forum and got some suggestions for a good alignment shop near here. I'd like to make sure everything is OK before I take it in again. The dealer did this as a quickie no-charge deal so I'm not going to complain.

Thanks!

 

Here are the specs for the C6. The Z is the FE4 suspension:


If the shop can't get more than -.13 degrees camber in the rear there is something wrong. If you notice the rear camber service preferred setting is -1.2 degrees so at -.13 you are way, way off. Even if you take the .6 tolerance range in you are way, way off.

Either the alignment tech doesn't know what he/she is doing or there is a mechanical problem the alignment tech should have brought to the attention of a senior tech. Unlike base and Z51 cars the Z06 has camber washers behind the rear upper control arms and these can be adjusted along with the lower control arm cam to set camber.

Bill

 

Interesting info. Their spec sheet calls out FE4 but the range doesn't quite match the figure - close, though. I need to flush the brake fluid very soon so I'll take a peek when I'm in there but I doubt I'll know what I'm looking at. The shop I was recommended supposedly has experience with newer Vettes so I may just have to lean on them a little.

Supposedly the tech did bring the issue to the attention of the higher-ups but no one could explain the error. The service writer brought it to my attention right away.

Thanks for info!!

For fun, according to the report, these are the "after" specs...
Front
Caster

• Left = 8.38
• Right = 8.80

Camber

• Left = -0.87
• Right = -0.73

Toe

• Left = 1/32"
• Right = 1/32"
• Total = 1/16"

Rear
Camber

• Left = -0.11
• Right = -0.60

Toe

• Left = 1/16"
• Right = 0"
• Total = 1/32"

Thrust angle = 0.06

 

Get a Pfadt alignment kit and use their specs. Works great!

 

Like some one else said you need a shop which will set the alignment correct not just within specs, you need to have it set up for your driving street or track and after the alignment the cambolts and nuts need to be torqued to spec. most shops yse the PDT method and the alignment slips
if the adjustments are tight they will stay