Front-wheel alignment

[MBnewbie123]

Hi folks,

I use a C-Class W204, and recently, I had to get two front tyres replaced. The inner shoulders had worn down to the wire! Yet the outer shoulder was fine. I could not have seen the state of the inner shoulder, unless, of course, I was looking for a problem with the tyres. The off-side (driver's side) tyre was slowly deflating, that prompted me to get someone to look at the tyres. The wear seems excessive.

Anyway, the guy that fitted the new tyres said that I might need to get the wheels realigned. The thing is when I am driving in a straight line and let go off the steering wheel, the car does NOT pull to either side. Could there be another reason for this? The car does not get used a lot, so the wear is not commensurate with the use the car gets.

If it is a wheel alignment problem, another problem I have, it seems, is that the car might have an AMG suspension kit on it and apparently Kwik Fit (they fitted the most recent tyres) cannot do the wheel alignment, and they said I would have to bring it to a Mercedes-Benz dealership to get the wheels aligned. Neither Kwik Fit nor I are certain if an AMG suspension kit is on the car, so, does anyone know how I can find out if I have one on the car? And, if I do, do I definitely need to bring it to a Mercedes-Benz dealership or do I have another choice?

Kind regards,

L.

 

[LostKiwi]

1. Find a better alignment specialist. There should be no difference in what suspension is fitted as to ability to align it. The only difference will be what settings are needed.
2. It sounds like the car has excessive toe out or excessive negative camber. Before doing anything else check both sides for broken springs. Then measure ride height to the top of the arch from the ground. Compare to specs. That will tell you if the car is lowered.

 

[Arv]

If there is no problem with the alignment, it could be the shocks that are bad.

 

[MBnewbie123]

If there is no problem with the alignment, it could be the shocks that are bad.

Hi Arv. Thanks for your reply. I am not sure if there is no problem with the alignment, and the car passed its MOT test (vehicle safety test in the UK) recently. Plus, it rides okay. So, I am not sure that is the shocks.

 

[Blobcat]

Hi Arv. Thanks for your reply. I am not sure if there is no problem with the alignment, and the car passed its MOT test (vehicle safety test in the UK) recently. Plus, it rides okay. So, I am not sure that is the shocks.

Do you brake late into corners? Do you accelerate whilst still having a decent amount of steering input? Do you have a lot of speed bumps that you straddle?

All of the above can lead to excessive and premature inner shoulder wear.

 

[MBnewbie123]

Do you brake late into corners? Do you accelerate whilst still having a decent amount of steering input? Do you have a lot of speed bumps that you straddle?

All of the above can lead to excessive and premature inner shoulder wear.

Haha, you know me then! I don't drive it too hard, but, yes, I brake late into corners, and I am not afraid of the throttle (with a bit of steering). But, while I drive fast, I try to do so with the philosophy of driving like everything (brakes, tyres, gearbox, etc.) is made of glass, so, I am not sure if that is the cause - but it could be! I just don't hoon the car, if you know what I mean. By the way, the slow deflation only happened on the driver's side. I did not see nor feel the other front tyre, so maybe it was fine. I also deal with a lot of speed bumps. I am curious, how do speed bumps cause excessive and premature inner shoulder wear?

 

[MBnewbie123]

1. Find a better alignment specialist. There should be no difference in what suspension is fitted as to ability to align it. The only difference will be what settings are needed.
2. It sounds like the car has excessive toe out or excessive negative camber. Before doing anything else check both sides for broken springs. Then measure ride height to the top of the arch from the ground. Compare to specs. That will tell you if the car is lowered.

Actually, the first point reminds me - I think they were unable to find the data they needed to do the alignment. I think my registration code was not allowing them to find it. I went to Kwik Fit, do you think they could find it using a VIN? I did think negative camber was causing the problem, because, and I may be wrong about this, the W204 has negative camber set into the car to assist with the turning at slow speeds.

I will check for broken springs too.

 

[Blobcat]

I am curious, how do speed bumps cause excessive and premature inner shoulder wear?

when you straddle a speed bump all the weight of the car is on the inner edge of the tyre. The tyre can also get squashed into the speed bump which if it isn’t particularly well fixed down can chew up the tyre as the tyre is forced into it.
In addition it’s a great way of cracking your alloy wheels as the inner edge isn’t supported by the spokes so bends and cracks.

 

[LostKiwi]

Actually, the first point reminds me - I think they were unable to find the data they needed to do the alignment. I think my registration code was not allowing them to find it. I went to Kwik Fit, do you think they could find it using a VIN? I did think negative camber was causing the problem, because, and I may be wrong about this, the W204 has negative camber set into the car to assist with the turning at slow speeds.

I will check for broken springs too.

Camber is used to correct for body roll at speed. As the car rolls so the strut 9n the outside of the corner moves towards a more positive setting. By setting static negative camber you can help offset some of the effects of body roll. As the suspension compresses camber will also go more negative. This why cars with lowered suspension often end up with too much static negative camber as the lowering mimics compression of the suspension.

This is why to check for a broken spring. As with lowering a broken spring will create more static negative camber.

In general the ideal will be to have slightly more negative camber than standard if lowering springs are fitted (typically 0.25 to 0.5°) and slightly more caster (0.5 to 1°).

There used to be a company called Wheels in Motion that were the dogs danglies for setting up Mercs but they're no longer trading.

Steve@Avantgarde motors near Bristol has a good reputation for setting Mercs up properly.

Also a regular on here.
@Steve@Avantgarde