FRONT end alignment for uneven REAR tire wear?

[YossiD]

2013 Suzuki S-Cross - front-wheel drive with semi-independent rear suspension.

I have just replaced two REAR tires that had worn unevenly - more wear on the outer edges.

The tire guy told me that I need a FRONT end alignment. Does that make sense?

I also asked the guy if the new tires shouldn't go on the front, as I remember that recommendation from years ago, but he said the new tires should go in the rear. What say you guys?

Thanks

[CapriRacer]

It's pretty common for the words "Front End Alignment" to be used when they just mean "Alignment". Old habits die hard!

The reason new tires should go on the rear is in an emergency maneuver you want the grip to be in the rear so the front stays in front. That way you'll have steering as soon as its available. Hard to drive a car when it's backwards.

[YossiD]

Thanks for the informative reply.

Do the folks who do front end alignments generally do rear alignments as well?

Anyway, I asked my mechanic about it. He had a look at the rear suspension and said all is well, and not to do anything.

Also, can you provide any insight as to why both rear tires were more worn on the outer edges?

[shorod]

You'll generally either be sold a front end alignment, a thrust angle alignment, or a 4-wheel alignment. Pretty much everything on the road these days should get at least a thrust angle alignment. Many front wheel drive and 4-wheel independent suspension vehicles are also capable of having a 4-wheel alignment performed.

Have you owned the Suzuki long enough to know whether or not the tires have been rotate recently? Maybe the tires now on the rear were previously on the front, and the wear occurred while on the front. If you know that to not be the case though, and the wear is only on the outer edge versus inner and outer edges, then you may want to either challenge the shop a bit more, or get a second opinion from a different shop. It would seem unusual for the shop to turn down the opportunity to sell a 4-wheel alignment (yes, they will cost more than a thrust angle alignment) unless they have really good margins on their tire sales....

-Rod

[maxwedge]

Just to add, if the thrust angle is off on a solid rear vehicle, really no way to correct that with an alignment, the axle is not square in the chassis. Independent rear adjustable suspension, ok. With solid rear axle vehicles we do a centerline alignment but note the thrust angle. Of course front wheel set back is also noted.

[YossiD]

I trust my mechanic, and if he says everything is ok, I believe him. He doesn't have the equipment to do front end alignments; I'd need to go to a specialty shop for that.

I bought this car new, but have never rotated the tires. Is it still recommended practice? My mechanic says that most people don't bother with it anymore, but if rotating, it should only be front to rear, so as not to reverse direction of tire rotation. I suppose it would also have to do with tread pattern. Do you guys agree with that?

According to some other websites, uneven wear on the outer edges of rear tires can be caused by overinflation. I would think the opposite. Comments?

Thanks to you all for your friendly and helpful replies.

[shorod]

It sounds like your "mechanic" just checked the rear suspension for any worn or obviously damaged parts. Since he doesn't have an alignment system he would have no way to tell you if the alignment in the rear is or is not "off." Oh, the reason I put "mechanic" in quotes above is not to question his capabilities, but rather because the more accepted term these days is "technician" since the skills needed to work on modern vehicles extends far past the ability to work on mechanical aspects, but also electrical and I would argue physical and mental since many items are pretty difficult to access and require good problem solving skills to diagnose and figure out how to replace, even with a good service manual.

If the wheels and tires are the same front and rear (size and offset), then rotating front to rear is, as far as I'm aware, still recommended. But be aware that the recommended tire inflation is not always the same front to rear, so keep that in mind when/if rotating. Since many tires are directional, front to rear rather than an 'X' pattern does seem to be more the norm. There are others in this forum that are more up-to-speed on modern tire technology that can confirm or correct my thoughts.

Uneven wear across the tire could be caused by over-inflation, but in that case the excessive wear area would be in the middle of the tread (still uneven across the tread). Excess wear on both outer edges (of a properly aligned vehicle) would typically be the result of under-inflation. Scalloping of the tread would typically be an alignment issue. There are some tire models that seem to be more subject to scalloping, but I suspect ultimately they were just more sensitive to a proper alignment.

Ultimately since you trust your mechanic/technician, ask them where they would recommend for an alignment and get your car aligned. Tires are expensive and the information you've provided would suggest that you will benefit from having an alignment performed. Make sure your tire inflation is set to the recommended pressure listed on the placard before having the alignment performed. Also if you are a larger person don't be offended if the alignment shop technician asks you your approximate weight. They may want to take that into consideration when performing the alignment.

-Rod

[maxwedge]

Well put, Rod.

[fredjacksonsan]

Agree with Rod -- rear tires have been underinflated for some time.

[CapriRacer]

Originally Posted by fredjacksonsan

Agree with Rod -- rear tires have been underinflated for some time.

So I'm going to disagree.

First, we don't know if the rear tires used to be on the front. That would explain why the tires might be worn the way they are worn.

Second, the affect tire pressure has on tire wear is usually exaggerated.

Ya' see, steer tires tend to wear on the shoulder and drive tires tend to wear in the center. This is a FWD, so the front tires are doing both, so the tire wear evens itself out - usually. The rear tires are just along for the ride and wear much more slowly - but interestingly, FWD cars don't seem to have problem with center wear like you'd expect if the rears were over inflated - which they would be in an unloaded FWD. That means the inflation pressure doesn't have as much effect on wear as people expect.

But if the car is driven in the city a lot, then the tendency for the fronts to wear in the shoulders gets more pronounced - and if those tires are rotated to the rears, that would explain why the rear tires have that kind of wear.

Let's see what the OP has to say about this.

[RidingOnRailz]

Originally Posted by CapriRacer

So I'm going to disagree.

First, we don't know if the rear tires used to be on the front. That would explain why the tires might be worn the way they are worn.

Second, the affect tire pressure has on tire wear is usually exaggerated.

Ya' see, steer tires tend to wear on the shoulder and drive tires tend to wear in the center. This is a FWD, so the front tires are doing both, so the tire wear evens itself out - usually. The rear tires are just along for the ride and wear much more slowly - but interestingly, FWD cars don't seem to have problem with center wear like you'd expect if the rears were over inflated - which they would be in an unloaded FWD. That means the inflation pressure doesn't have as much effect on wear as people expect.

But if the car is driven in the city a lot, then the tendency for the fronts to wear in the shoulders gets more pronounced - and if those tires are rotated to the rears, that would explain why the rear tires have that kind of wear.

Let's see what the OP has to say about this.

The title of this thread alone makes me dizzy - and suspicious!

[fredjacksonsan]

Originally Posted by CapriRacer

So I'm going to disagree.

First, we don't know if the rear tires used to be on the front. That would explain why the tires might be worn the way they are worn.

Second, the affect tire pressure has on tire wear is usually exaggerated.

Ya' see, steer tires tend to wear on the shoulder and drive tires tend to wear in the center. This is a FWD, so the front tires are doing both, so the tire wear evens itself out - usually. The rear tires are just along for the ride and wear much more slowly - but interestingly, FWD cars don't seem to have problem with center wear like you'd expect if the rears were over inflated - which they would be in an unloaded FWD. That means the inflation pressure doesn't have as much effect on wear as people expect.

But if the car is driven in the city a lot, then the tendency for the fronts to wear in the shoulders gets more pronounced - and if those tires are rotated to the rears, that would explain why the rear tires have that kind of wear.

Let's see what the OP has to say about this.

He already DID say something about this:

Originally Posted by YossiD

...

I bought this car new, but have never rotated the tires.

...

Now I'm starting to think we're discussing a bot's post.