Uneven wear on tyres

[After Shock]

I'm getting very uneven wear on all four tyres.

I had four wheel alignment carried out and that looks fine although I'm going to repeat this.

Everything else seems ok.

The inner edges are wearing a lot quicker than they should though.

I put aftermarket wheels on. 8 and 9 inch staggered but I can't see this as the problem.

I'm lost. Anyone any thoughts??

 

[MancMike]

Have the ball joins got play in them, or have you got wheel spacers on?

 

[After Shock]

Ball joints are ok.

No spacers.

 

[wheels-inmotion]

How different are the wheel off-sets compared to the OEM wheels?

 

[After Shock]

How different are the wheel off-sets compared to the OEM wheels?

This was nagging at the back of my mind!

I can't recall the numbers. I ordered them after market from an EBAY company.

So would this show up as uneven wear even if the tracking is showing ok?

Thsnks

 

[MancMike]

Yeah for the same reason as if using wheel spacers. If they're further out from the hub they'll be levering outwards against all the joints more than they should, giving you negative camber which is what you've described with wear on inner edges. So see if you can find the offset.

What sort of tracking did you have? Generally quick, cheap tracking just checks toe-in, toe-out, but might not have checked the camber, which *must* be out if you've got wear on the inner edge.

 

[After Shock]

Yeah for the same reason as if using wheel spacers. If they're further out from the hub they'll be levering outwards against all the joints more than they should, giving you negative camber which is what you've described with wear on inner edges. So see if you can find the offset.

What sort of tracking did you have? Generally quick, cheap tracking just checks toe-in, toe-out, but might not have checked the camber, which *must* be out if you've got wear on the inner edge.

I'm going to look back to find offsets. I spent a long time checking and double checking when I purchased them though to make sure I got this right. Now to double check!!

I had four wheel laser alignment done correctly. Camber was checked and looked in "the green" which is what is really throwing me!

I'm going to try to get this checked later today.

thanks

 

[John]

What sort of tracking did you have? Generally quick, cheap tracking just checks toe-in, toe-out, but might not have checked the camber, which *must* be out if you've got wear on the inner edge.

I thought inner edge wear could occur with too much toe-in alone.

Learn something new.

 

[Mrhanky]

You really want to get it on a hunter machine which does 4 wheel alignment. FYI most Kwik fits now have Hunter machines.

Regards checking camber yes the above will check this. However unless you have adjustable camber arms most cars wont allow this to be changed. Therefore its fine knowing its out but you cant do anything about it.

 

[MancMike]

I thought inner edge wear could occur with too much toe-in alone.

Learn something new.

Oh I'm not saying it can't, I just ruled that out as the OP said all four wheels, which toe-in/out is more likely to be just the front wheels, and as they're after market alloys, and all four wheels are wearing incorrectly, I'd think it much be negative camber rather than toe-in.

 

[V12]

On a 210 I wouldn't be too concerned about wrong offset wheels. I know from experience that there is little wiggle room to play with in the arches of a 210. On the front, just a little too high an offset and the wheels touch the top suspension and slightly too low and they are touching the arches.

I've not known 5mm offset either way to cause real problems for inner tyre wear.

 

[V12]

You really want to get it on a hunter machine which does 4 wheel alignment. FYI most Kwik fits now have Hunter machines.

Regards checking camber yes the above will check this. However unless you have adjustable camber arms most cars wont allow this to be changed. Therefore its fine knowing its out but you cant do anything about it.

Eccentric bolts?

 

[BlackC55]

Check the castor bushes. They crack and cause weird handling and tyre wear on the inside. The only way to check them is to lever the arm over.

We see this so many times. Wheel alignments get done and the suspension has wear in it.

 

[Mrhanky]

Eccentric bolts?

Yep good mention, depends on how much adjustment you need.

 

[wheels-inmotion]

You say the camber positions were in the green, at what area in the green were they? Are they near the maximum negative or minimum positive?

Wheel off-sets are a constant problem within the industry, reason being the same chassis can be offered lets say 16" 7j wheels up to 18" 9.5j wheels but the geometry positions remain the same, well how can that be?

By design ( initially ) the front camber position and projected inclination of the lower ball joint offer a contact patch under the steer axis called the scrub radius. The SR distributes the cars weight evenly and during yaw migration during a turn but if the off-set is changed then the distribution must be incorrect hence the wear.

The position of the SR can be measured but common sense by a good tyre shop would know the SR needs to be re-directed by moving the camber position.

 

[After Shock]

The problems seemed to start when I had new front springs fitted. This altered all of the front set up to a degree. Once sorted and set up "by eye" I took the car over to my tyre place. ETB Tyres. They use Hunter laser as mentioned.

The camber was way out!

Eccentric bolts have been mentioned. We got a set of these looked to fit them only to find a set in situ. Bodged in and not removable or adjustable! Back to trying to get it right "by eye" as the alternative is 4 new arms at £150 each plus fitting which is difficult too!

Laser said YES! Deep sigh. Tipped the guy who checked it £20 notes as I'd been back and forth and he'd been really helpful and just saved me a grand.

You say the camber positions were in the green, at what area in the green were they? Are they near the maximum negative or minimum positive?

Wheel off-sets are a constant problem within the industry, reason being the same chassis can be offered lets say 16" 7j wheels up to 18" 9.5j wheels but the geometry positions remain the same, well how can that be?

By design ( initially ) the front camber position and projected inclination of the lower ball joint offer a contact patch under the steer axis called the scrub radius. The SR distributes the cars weight evenly and during yaw migration during a turn but if the off-set is changed then the distribution must be incorrect hence the wear.

The position of the SR can be measured but common sense by a good tyre shop would know the SR needs to be re-directed by moving the camber position.

Thanks for this as I'm guessing this is the problem!??! I've gone up to 8" and 9" staggered 18" wheels from the 17" wheels it had on when I purchased it.

I'm guessing I now need to be exact centre green? As going to the edges of the green "ok" margin is to far out and scrubbing the inner edges?

Do I need to be almost exact dead centre then do you think?

Hope to get to ETB tomorrow so will see! Cross your fingers folks!

 

[V12]

What offset are the new wheels then?
The OEM 17" wheels are either 7.5J or 8J wide and ET37 offset.
The 18" AMG wheels are 8J and ET31 on the front.
Have seen dozens of cars with these over the years that don't wear the inside edge.

I still don't believe the wheels are the problem myself.

 

[After Shock]

What offset are the new wheels then?
The OEM 17" wheels are either 7.5J or 8J wide and ET37 offset.
The 18" AMG wheels are 8J and ET31 on the front.
Have seen dozens of cars with these over the years that don't wear the inside edge.

I still don't believe the wheels are the problem myself.

I hope you are right as I looked very carefully for compatible wheels!

Worryingly I'm back to camber adjustment that is going to be horribly expensive!!

 

[After Shock]

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[wheels-inmotion]

I seriously don't want to over complicate things but it's not an easy topic.

As said the scrub radius is a projected contact patch under the steer axis that distributes the cars weight during straight line travel and yaw. It does have a tolerance +- 10mm ( globally recognized ) thereafter tyre wear or handling is impaired.

Given the description it seems the SR is + or outside of the steer axis in which case the camber needs to be reduced toward positive, forget about the OEM centre point that's irrelevant now. The MB replacemment adjuster bolts are not eccentric but a male/ female alignment that allows up to 30' of geometric movement ( camber alone ) 45' if the castor is also adjusted.