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Both of my front tires (a few years old) have been wearing on the outside in a strange way. I'd like to know if any one has seen this before and what could be the cause. The tire wear is pretty much even across the surface, but the outside looks like someone went to town on it with a razor blade. Thoughts?

Thanks.
 

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Both of my front tires (a few years old) have been wearing on the outside in a strange way. I'd like to know if any one has seen this before and what could be the cause. The tire wear is pretty much even across the surface, but the outside looks like someone went to town on it with a razor blade. Thoughts?

Thanks.
What kind of tires are those? Is your car lowered and/or somehow rubbing on something around the wheel well?

It looks as if the tires are shredding apart lol can't be good
 

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I'd put my money on messed up toe.




PLEASE NOTE THAT I DO NOT OWN AN M5 AND THIS POST IS NOT INTENDED TO BE ARROGANT. PLEASE READ THE IMPORTANT REVISED DISCLAIMER THAT APPLIES TO THIS POST
 

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Tires are pilot sport a/s. So I should have it aligned? If yes can any alignment shop get thus right?

Yes. But just because any shop CAN get it right does not mean taking it to any shop WILL get it right.


Spend 2 hours and RESEARCH "alignment" here. Unless you are tracking the car, have it set to minimum toe- plenty of discussions.
 

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Tires are pilot sport a/s. So I should have it aligned? If yes can any alignment shop get thus right?
+1 on what others have said about alignment. A background factor is those tires. In my experience those tires are bad for breaking apart like that when stressed (and old). The rubber seems really hard. Pilot super sports or Conti extreme contacts would just show a more mild scrub, not those chunks breaking off like that.
 

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Over all the years, the biggest issue I've seen with alignments is that "shops" use the factory specifications, but they do not load the car properly as specified (weights in cabin and trunk including full gas tank). This always results in too much rear camber and too much rear toe, especially under load.

As far as that pic goes, it does look like an awful amount of toe-in; you should check the thrust bushings and center track link and tie rod ends closely. If there is any wear/play in these, replace them all before aligning the car.
 

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Over all the years, the biggest issue I've seen with alignments is that "shops" use the factory specifications, but they do not load the car properly as specified (weights in cabin and trunk including full gas tank). This always results in too much rear camber and too much rear toe, especially under load.

As far as that pic goes, it does look like an awful amount of toe-in; you should check the thrust bushings and center track link and tie rod ends closely. If there is any wear/play in these, replace them all before aligning the car.
This is key advice. Check those bushings and tie rods *first*. With worn/loose components, the alignment won't do any good.
 

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. This always results in too much rear camber and too much rear toe, especially under load.

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Just a quibble...i tend to disagree.

If you load the car and then set camber, then unloaded camber will be MORE. So failing to load it will result in less camber.

I load the car the way it is driven- one person (not 5 with golf clubs and luggage...). Seems to work fine for the last 153k miles.:)

100% agree factory spec allows too much toe- everyone sets it "to the middle" as this is easier and it chews tires. Toe, small tires up front, lower inflation pressure (and crappy rubber) can lead to tires that are beat up on the outer edge
 

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Toe in will do that. Get an alignment or try the caveman method.
 

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Just a quibble...i tend to disagree.

If you load the car and then set camber, then unloaded camber will be MORE. So failing to load it will result in less camber.

I load the car the way it is driven- one person (not 5 with golf clubs and luggage...). Seems to work fine for the last 153k miles.:)

100% agree factory spec allows too much toe- everyone sets it "to the middle" as this is easier and it chews tires. Toe, small tires up front, lower inflation pressure (and crappy rubber) can lead to tires that are beat up on the outer edge
The point I was making was that the BMW spec calls for -1.8 to -2.0 in the rear in their loaded condition; they did this full well knowing that the majority of the time a car will not be loaded to the alignment spec level. Hence their goal was to arrive at ~1.5 rear camber under typical conditions, *and* to prevent a fully loaded up car from exceeding -2.0 very much (i.e. gross vehicle weight type loading).
 
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The point I was making was that the BMW spec calls for -1.8 to -2.0 in the rear in their loaded condition; they did this full well knowing that the majority of the time a car will not be loaded to the alignment spec level. Hence their goal was to arrive at ~1.5 rear camber under typical conditions, *and* to prevent a fully loaded up car from exceeding -2.0 very much (i.e. gross vehicle weight type loading).
So the BMW service manual assumes that people do not follow the procedures set forth in the service manual and because of this BMW purposely uses incorrect specs so that when people ignore the procedures they will end up with the correct results? What about people that follow the procedures, what specs should they use? They must have another version of the service manual for people who actually follow the procedures with the unmodified specs.



I feel like I have been living a lie :eek:

THERE IS NO TRUTH!

:rofl:



Maybe when they specified TWS 10w60 they knew that most people would use something else and BMW rally wanted people to use 5w30 all along but they knew that if they specified 5w30 people would actually use TWS 10w60. It is all starting to make sense now........



PLEASE NOTE THAT I DO NOT OWN AN M5 AND THIS POST IS NOT INTENDED TO BE ARROGANT. PLEASE READ THE IMPORTANT REVISED DISCLAIMER THAT APPLIES TO THIS POST
 

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So the BMW service manual assumes that people do not follow the procedures set forth in the service manual and because of this BMW purposely uses incorrect specs so that when people ignore the procedures they will end up with the correct results? What about people that follow the procedures, what specs should they use? They must have another version of the service manual for people who actually follow the procedures with the unmodified specs.

I feel like I have been living a lie :eek:

THERE IS NO TRUTH!

:rofl:
What? That's not what I said at all. BMW created a spec that allows for a moderately loaded car to have its alignment set at the "specified values". They know that, on average, that will be close to what the car sees in a range of typical use.

What happens is that "an alignment shop" (which definitely includes dealerships) ignores the whole portion of the spec with the weighting of the car inside and in the trunk and having a full gas tank. Then said mechanic pays attention to the BMW spec for the settings; hence what I was saying above -- when the car is aligned this way, once you do load it up with a full tank, 4-5 passengers, full trunk, you're way past the intended range of rear camber and toe-in. Even if you then just loaded to their spec weight values in the alignment spec, the alignment will be significantly off the specified values. ;)

The point is that there is a rhyme/reason to their spec. Unfortunately, few pay attention to the spec and then wonder why they have issues later on (the most common one I've seen on the board over the past 12 years is inside rear tire wear).
 

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Hmmmmm. Ok, so the BMW service manual doesn't lie, that is a relief.

So it seems like the e39 M5's suspension is pretty sensitive to weight. What happens when the car is set up properly using the service manual procedure and then driven with one passenger, no luggage and a half full tank - seems like that would throw off things a lot as well. Also, when people install a nice "performance" suspension set up on the car (everyone knows that the stock M5 suspension is hardly sporting) with much stiffer springs, it would seem that changes in weight would have much less of a change in the suspension geometry so that the weight of the car when aligned would not matter as much - yet another benefit of a nice stiff "sporting" suspension, along with the great ride :).

It seems that we have found yet another area where the e39 M5 requires a lot of care and really can't be dealt with effectively our in the field, or at your local BMW dealer :(




PLEASE NOTE THAT I DO NOT OWN AN M5 AND THIS POST IS NOT INTENDED TO BE ARROGANT. PLEASE READ THE IMPORTANT REVISED DISCLAIMER THAT APPLIES TO THIS POST
 

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that chunking is very very common in this Michelin tire, it does look like your toe is out but that chucking wouldn't be cause by toe unless your frontend is absolutely hammered. those Michelin tires in specific do not like corners. as far as alignment goes as people have said before get inspect all the parts that will affect the alignment. (bushings, ball joints, tie rods) and proper tire inflation before you have the shop do the alignment.
 

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Loading the car with weights is to replicate "what if I had the car loaded to max capacity with people and luggage"
In my opinion, this is not the most likely scenario of how the car is most often driven, at least for me.
In my case, the car might as well have only come with a driver seat lol so if I was to weight mine I would only do the driver weight to be more realistic to what my actual ride position is
 
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