Tire wear and alignment

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A vehicle I take care of got aligned recently because when I drove it, I could feel it was off.

The alignment sheet is below. My question is, what here would cause the outside of the right front tire to wear excessively? The camber and toe specs don't look funky enough to cause issues. The wear was not caused by making lots of left turns, for reference.

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.20 degree of toe in will destroy the outside edge of a tire.

For reference:

Negative toe = toe out = worn inside tire edge
Positive toe = toe in = worn outside tire edge

.20 degree is A LOT of toe in.
 
Your toe was .60 in degrees from nominal which should give lots of wear on the outboard shoulder. The right side wore more than the left because it had less air in it. The oleft front tire did the steering and the right front got dragged across the cheese grater road.
 
Thank you for the responses. I do not know much about what "good" or "bad" is, just to what the different specifications refer. I'm amazed that 0.2 degrees of toe is enough to cause such an issue but not surprised, I guess.
 
Originally Posted By: yonyon
Your toe was .60 in degrees from nominal which should give lots of wear on the outboard shoulder. The right side wore more than the left because it had less air in it. The oleft front tire did the steering and the right front got dragged across the cheese grater road.


Where does the 0.60 degrees come from? I want to know what to look for in the future.
 
You had 0.45 degrees of total toe (not sure where 0.60 is coming from either), which is a lot, but as you can see, not excessively far out of range. You're "allowed" to have as much as 0.35 degrees of total toe apparently.

What type of vehicle is this? As it sits, you have 0.05 degrees of static toe. If this is a RWD vehicle, that's about perfect (for tire wear), as the toe will naturally want to go negative as you roll down the road from rolling resistance. If this is a FWD vehicle, I would prefer even less toe than that, preferrably closer to zero toe, or maybe even slightly negative. With a FWD car, the front tires pull the car down the road and toe will try to go positive. How much it goes negative or positive depends a lot on the rate of the compliance bushings. Softer bushings allow for more dynamic alignment changes.

As an aside, your car probably felt like it had great steering response before (positive toe will feel that way). It may feel like it has a little less steering response now. The effect an alignment can have on the "playfulness" of a chassis is amazing.
 
It's anything but a "playful" vehicle.

I noticed excessive tire wear on the outside of the front right tire and that it was pulling to one direction. Willingness to change directions, I don't know - it's an appliance.
wink.gif


It is a Malibu, for what it's worth. I doubt it had ever been aligned before this (which was a while ago, I was just presented with the sheet now) but I did not ask and don't know as it is not my vehicle.
 
Given that this is a FWD vehicle, the dynamic toe is probably more severe than the static toe, which really explains the heavy outside wear of the front tires.

What's most interesting to me is the rear alignment range seems to call for a touch of negative toe (toe out). This is rather uncommon for IRS vehicles. Toe in is typically specified for high speed and transitional stability.
 
Having a bit of toe out on the rear sounds about right. The dynamics of the car are actually a bit bizarre in my experience. It's very stable on the highway (very good long distance vehicle in my experience) but it also darts quite eagerly compared to our Accord. It's odd in that I'm not sure how the actual handling compares between the Accord and Malibu. I actually suspect the Malibu can corner faster and brake better than the Accord but driving the two the early impression is the opposite - the Accord is a lot more dynamic "feeling". In other words, the Malibu undersells its capabilities and the Accord oversells them.
 
In an emergency situation, I would think that negative rear toe would encourage oversteer. There must be a lot of toe change with suspension travel on the back of the Malibu. That is, as the rear suspension compresses, the toe will change from negative to positive (toe in).

Most cars with IRS will specify some toe in. That's what surprises me about this setup; it's the first I've seen that calls for rear toe out.
 
One thing is if I'm remembering right GM FWD cars like the Malibu have a slight negative scrub radius on the front suspension so this tends to impart a toe in force.

The Malibu has a lot of caster for FWD car contributing to its good highway stability. A little toe out on the rear makes a lot of sense. It would encourage turn in, but like you mentioned at higher cornering speed the rear suspension would rollsteer more toe in.

I think the N-car's ride and handling is commonly underrated. The wheels were pushed outward and I think good choices were made in spring, shock valving, and bushing rates. And the steering feel isn't bad either.
The Grand Am and Alero N-cars were even better being lower slung than the Malibu and with available 50 series tires, firmer shock valving, rear disk brakes and variable-assisted steering etc. I think an '01 or '02 Grand Am drove and rode better than comparable Accords.
 
Thank you for all the learning about suspension design.

Admittedly the Accord is a newer generation than the Malibu (ours is a 2003, the first of that generation). I don't know if I'd call the steering feel great on the Malibu but the Accord isn't great either. My car is RWD and is known for having sloppy bushings and it's worlds better than any front-driver.

The biggest difference between the two cars is the horsepower. The Accord will blow the doors off the Malibu with no real expense to fuel economy. The around town mileage on the Accord is a little less but highway is fairly comparable.

This is pretty far off topic I suppose. But they were somewhat competitors in their time.
 
Originally Posted By: yonyon
Your toe was .60 in degrees from nominal which should give lots of wear on the outboard shoulder. The right side wore more than the left because it had less air in it. The oleft front tire did the steering and the right front got dragged across the cheese grater road.


No. There was no 0.60 deg toe.
So disregard this.

The total toe was .45 deg. Not horrible, but pigeon toed a bit. I really don't see why there was wear on the right - the left was actually out of spec a bit more.
But remember ' -X [neg]' toe is splayed out, and 'X' toe is in. Therefore your initial pre adjustment setup would wear tires on the outside edge more.

Is this a FWD car? Then the tires are pulled into more pigeon toe when under power, making it worse. Zero or a bit out is good for most FWD passenger cars.
FWD cars Do wear the edges - the nature of the beast. We can try to minimize this.

Tire pressure kept up to date? This can account for wear.
So can more 'slop' in your right side - it pulled in more when driving.
Static alignments check only that - sitting still. Under power, things change. And I can change most car's alignment up to 1/2 deg by pulling/pushing on the tires as they sit [when i let go].
 
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Thank you for the response, mechtech.

I think the biggest issue I had when looking at these numbers was simply knowing whether positive numbers on toe and caster were in or out.

The car doesn't typically wear tires on the outside edge - this happened sort of all at once. It is due for new tires and I did not want the new tires to be doing the same thing.

I do find it annoying that FWD cars wear the outside edges so much but I suppose that's the nature of the beast with the front wheels pulling and typically monstrous weight imbalance.
 
Not only did they fix your toe, but they also improved your camber. You were sitting with a touch of positive camber in both front tires, which would tend to wear the outer edges of the tread more. This is also common with FWD cars. They gave you some negative camber on both sides in the front, and that will also improve tire wear (and handling).
 
Originally Posted By: Hokiefyd
Not only did they fix your toe, but they also improved your camber. You were sitting with a touch of positive camber in both front tires, which would tend to wear the outer edges of the tread more. This is also common with FWD cars. They gave you some negative camber on both sides in the front, and that will also improve tire wear (and handling).


Camber is not a tire wearer, unless REALLY bad.
Certainly 1/2 deg either way will make no difference.
TOE is the tire killer.
 
The shop probably didn't adjust the camber. It is like pulling teeth to get most alignment techs to adjust camber and if the car has original struts it's usually not possible to adjust camber without filing out the strut mounting hole.

The thing about alignment print outs is you could have a car with even bent suspension parts and the alignment guy can jimmy the wheel and get whatever camber and caster reading they want.

Again, I'd say the toe being off was the cause of the tire wear and the camber looks like it is a little neg and at typical factory setting where you want it. So if nothing is worn then it should be ok after the toe alignment. Sometimes a big bump might ever so slightly jars the rack in it's mounting bolts enough or what have you gets slightly tweaked to throw toe out of specs.
 
I'd love to find a good alignment shop. Sometimes I wonder about the ball joints and tierod ends on my truck but every place kept telling me they were still okay. With 370k miles I don't know how they are.
 
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