alignment vs. rotation vs. tire wear?

AltinD · December 16, 2014, 06:01:44 AM

^^ In my case the inflation is correct as per recommended specs. Previously both of them were wearing almost the same. This time the rear one on the driver's side was worn more than the other

MX793 · December 16, 2014, 07:05:07 AM

What about the tires themselves? Are they worn evenly across? Is one side or shoulder wearing faster than the other? Which side (inboard or outboard)? Or is the wear symmetrical about the center of the tire (both shoulders wear faster than the center or center faster than the shoulders)?

Soup DeVille · December 16, 2014, 07:05:39 AM

All those specs look very mild. Nothing there I would expect to cause serious wear problems. It's not uncommon for camber from the factory to be non adjustable, especially on McPherson/chapman struts.

The problem may be with the brakes or the AWD system.

AltinD · December 17, 2014, 01:41:31 AM

Quote from: MX793 on December 16, 2014, 07:05:07 AM
What about the tires themselves? Are they worn evenly across? Is one side or shoulder wearing faster than the other? Which side (inboard or outboard)? Or is the wear symmetrical about the center of the tire (both shoulders wear faster than the center or center faster than the shoulders)?

I did explain in the previous post.

1. BOTH rear tires evenly consume more throughout the surface than the front ones

2. Additionally BOTH rear tires consume more at the inner side compared to the rest of the thread (an area less than 1 inch wide)

3. The rear tire on the driver's side consumed even more at the inner side than the other one. The wire mesh was exposed (it didn't yet on the other tire)

This is a pic when it happen previously, but the pattern of consumption is the same:

You can notice the tread consumption is less on the outer part of the tire and start increasing going inward, till it culminates with the exposing of the wire mesh at the inner side.

AltinD · December 17, 2014, 01:46:43 AM

Quote from: Soup DeVille on December 16, 2014, 07:05:39 AM
All those specs look very mild. Nothing there I would expect to cause serious wear problems. It's not uncommon for camber from the factory to be non adjustable, especially on McPherson/chapman struts.

The problem may be with the brakes or the AWD system.

What you mean with breaks? That they may be weaken and the tires scratch the surface and consume more? I certainly don't experience any tire squeal during braking or acceleration, I used to in the past when the tires were wearing evenly, so I know when it happens.

Can a problem with the suspension arms also give this kind of effect as well? For example if the stiffness is reduced and chassis inclines backward possibly applying more weight to the rear axle?

Soup DeVille · December 17, 2014, 01:59:37 AM

Quote from: AltinD on December 17, 2014, 01:46:43 AM
What you mean with breaks? That they may be weaken and the tires scratch the surface and consume more? I certainly don't experience any tire squeal during braking or acceleration, I used to in the past when the tires were wearing evenly, so I know when it happens.

Can a problem with the suspension arms also give this kind of effect as well? For example if the stiffness is reduced and chassis inclines backward possibly applying more weight to the rear axle?

If the brakes are dragging and not releasing completely, it could cause excessive wear (on the tires and the brakes). That would not necessarily cause any squealing noise.

The center or rear differential not operating properly could also cause excessive wear.

Usually I would suspect a suspension problem, but it looks like you've already had that inspected.

AltinD · December 17, 2014, 06:32:13 AM

Actually I haven't had that inspected, although at a previous maintenance servicing visit at the dealer I have asked them to check the problem (tire excessive consumption at the rear) so I'd suppose they will inspect the cars mechanical that can cause such problem. Actually they are supposed to inspect it as part of the service so i doubt they skipped on checking the brakes and or differential or even suspension.

However I do remain cynical to what they do or are capable to. Once they missed an overly consumed pad during service and I was left with calipers grabbing the rotors and as a result I had to replace the complete brake assembly at that wheel. They also failed to find a TPMS fault (even after replacing the sensors and the controller unit) and I opted to just deactivate the function instead of having to pay for them to open and inspect the entire wiring

AutobahnSHO · December 17, 2014, 07:00:59 AM

my problem was a horrible alignment.

No problems since this last one, in November. Tires aren't wearing abnormally.

S204STi · December 25, 2014, 11:59:59 PM

Quote from: AltinD on December 16, 2014, 03:44:57 AM

The technician this time said that the camber cannot be adjusted in this car, I have no idea how that can be possible. A previous alignment from the VW service center made no difference or change in tire consumption patterns.

That's actually pretty common. Typically however one can find aftermarket parts which allow for camber or toe adjustment.

Here's the thing to consider: alignment specs from the factory have to compromise between two different missions; stability in terms of vehicle handling, straight-line tracking, etc; and tire wear. Notice how your nominal camber front to rear is split by about a degree negative? That is there to promote straight-line stability, as well as creating a tendency towards understeer at the limit. A car can be "in-spec" but still chew up tires. Some cars are just like that. You could ask them to set toe to 0 in the rear and see if that helps.

S204STi · December 26, 2014, 12:01:05 AM

Also, christ man, check your tires out more frequently. You should never be surprised by tires hitting the belts...

12,000 RPM · December 30, 2014, 08:16:10 AM

Yea that is pretty crazy

Z is at the shop for an inspection... alignment is all over the place

Toe is off in front and left rear has a ton of camber. Tires got a little chewed up. O well

AltinD · January 15, 2015, 04:12:24 AM

Quote from: S204STi on December 25, 2014, 11:59:59 PM
That's actually pretty common. Typically however one can find aftermarket parts which allow for camber or toe adjustment.

Here's the thing to consider: alignment specs from the factory have to compromise between two different missions; stability in terms of vehicle handling, straight-line tracking, etc; and tire wear. Notice how your nominal camber front to rear is split by about a degree negative? That is there to promote straight-line stability, as well as creating a tendency towards understeer at the limit. A car can be "in-spec" but still chew up tires. Some cars are just like that. You could ask them to set toe to 0 in the rear and see if that helps.

VW Service center said to do anything they have to send the alignment readings to the central VW service in Germany and than wait for their instruction on how to solve the problem, which in itself it will take days to a week, or even more. I didn't let them do it, maybe next time I will send the car for scheduled maintenance (which should be in around 6 month).

The car did not have any problem in the first 3 years of its life, only later it started. Now I can see clearly that the real wheels/tires are off and angled

Quote from: S204STi on December 26, 2014, 12:01:05 AM
Also, christ man, check your tires out more frequently. You should never be surprised by tires hitting the belts...

I know ..... though hitting the belts wasn't what surprised me, irregular wear was/is.

Now that I'm thinking, before when I had no alignment problems a tread-consumed set of tires would slightly spin and squeal under aggressive start, now that they get un-even tread wear they never do that again. No idea why or what it means.