very bad tyre wear...

[Diablo]

Guys,

I at a bit of a loss as to why I am getting such wear on my fronts. The MOT tester noted that the extreme inner shoulder of both front tyres has worn away. The remaining parts of both tyres have circa 4-5mm left on them.

I have not had the tracking re-checked, but seems unlikely IMHO that both front wheels would be out by exactly the same amount. Nothing else was picked up on the MOT.

Any suggestions would be greatly appreciated.

[HPsauce]

MOT doesn't check the tracking so that's the first thing I'd get done.

[ainarssems]

I have not had the tracking re-checked, but seems unlikely IMHO that both front wheels would be out by exactly the same amount

That's exactly what happens if tracking is not right ( too much TOE OUT ).

It can also be due to suspension bush wear or if TOE constant S setting is not performed when doing wheel alignment. And in my experience 9 out of 10 garages doing wheel alignment don't even know what constant S is so it's often not done and many Audis that share this suspension design and Passats have this issue because of constant S adjustment not being done.

[David's8]

Ainar raised this issue about the Constant S alignment when I posted about wheel alignment after a track rod end replacement. I talked to the indy garage and it appears that it wasnt done. I did some further research

The explanation of why its required:
Bump or rebound alters the toe-in as a function of the bump and rebound travel. The resultant toe values are referred to as the toe-in curve.
The change in toe constant "S" is set with the vehicle raised by way of vertical adjustment of the track rod end. The wheel alignment computer determines the toe constant "S" by way of one measured value in the initial position and one when raised. In doing so, the actual values are compared to the specifications and displayed on the monitor.
Different adapters are required for raising depending on running gear .
Incorrect adjustment of the toe constant will result in inaccurate steering on braking/accelerating or driving over an uneven surface.


Elsa web shows how it is done:
http://elsaweb.spaghetticoder.org/do...F-F/20839457/2

The attached file is an alignment procedure for VAG vehicles. It mentions different vehicles so I am not sure how specific it is. It states the conditions after which alignment AND S-point adjustment is required. (i.e. replacement of specific components and, of course uneven tyre wear!)

[Architex_mA8tey]

Originally Posted by David's8

Ainar raised this issue about the Constant S alignment when I posted about wheel alignment after a track rod end replacement. I talked to the indy garage and it appears that it wasnt done. I did some further research

The explanation of why its required:
Bump or rebound alters the toe-in as a function of the bump and rebound travel. The resultant toe values are referred to as the toe-in curve.
The change in toe constant "S" is set with the vehicle raised by way of vertical adjustment of the track rod end. The wheel alignment computer determines the toe constant "S" by way of one measured value in the initial position and one when raised. In doing so, the actual values are compared to the specifications and displayed on the monitor.
Different adapters are required for raising depending on running gear .
Incorrect adjustment of the toe constant will result in inaccurate steering on braking/accelerating or driving over an uneven surface.


Elsa web shows how it is done:
http://elsaweb.spaghetticoder.org/do...F-F/20839457/2

The attached file is an alignment procedure for VAG vehicles. It mentions different vehicles so I am not sure how specific it is. It states the conditions after which alignment AND S-point adjustment is required. (i.e. replacement of specific components and, of course uneven tyre wear!)

Good info chaps
Would be good to know if the outcome ties in with this Diablo when you've got to the bottom of it

[Iyole]

Great Info all round .... thanx Gents ...

I also had bad wear on the inner part of the passengers side front tyre.
To my horror when I fitted the new Vredensteins It was evident that the
tyre had worn down to the canvas whereas the rest of the tyre had
above minimum tread on it.

According to my local dealer it was caused by a worn upper control arm.
Replaced them all round and problem appears to be resolved.

[Diablo]

Guys,


I really appreciate the inout.

I just went to get the tracking done and found that it was OK. They noticed that the bushes on the front/lower track control arms were split. He could not see the rears, but assumes that they may also be shot.

What is the best source of these bushes, or do you need to replace the entire arms?

Many thanks.


16/5/13 Just as a follow up to this: After them diagnosing the above suspension problems, I took the car to my trusted mechanic to get his opinion. He told me that all of the components mentioned were in perfect working order....

[Diablo]

Guys,
Just to close the loop on this one: I had the 4 wheel alignment done at Slough Audi. The camber was out on LHR and toe was out on RHR, so the car was effectively steering form the rear. This is after being told by my local alignment centre that the geometry was near perfect on my car and that I must have worn suspension components.

In short, the difference is amazing. It's too soon to say whether or not it will fix the wear problem, but after speaking to the Tech, I suspect it will. I also started getting a whirring noise coming from the rear, which too has now gone.

The total cost: £102, which includes them checking ride heights, test driving the car a complementary clean and vac. Incredible value for money, in my opinion, and exemplary customer service from Clare in the Service department. In comparison, Audi West London quoted me £400 to have the same work done.

[Adrian E]

That's not too bad at all - I've been quoted silly money at Crawley Audi in the past. They give you a starting figure including a couple of adjustments which runs to £200+ and then say each additional adjustment with bx £x extra! License to print money.....

[Diablo]

Originally Posted by Adrian E

That's not too bad at all - I've been quoted silly money at Crawley Audi in the past. They give you a starting figure including a couple of adjustments which runs to £200+ and then say each additional adjustment with bx £x extra! License to print money.....

I totally agree. One of the reasons for using my local alignment centre in the past was that they have a fixed price. The slight open ended approach of cost/adjustment, that most main dealers have, never really appealed to me. So, to get this all done for a reasonable fixed price by a main dealer is great. It is the best £100 I have spent on this car, by far…