2015 Outback tires cupping - tires....or suspension

[Rhill]

Hi guys, our 2015 Subaru's tires have cupped and have become loud AH!

The car only has 100k miles, and I've maintained it like a switch watch. The tires are Kumho Road Venture and are known to be loud.....and I'm guessing begin to cup. They have roughly 40k miles on them and have been rotated every 5-6k.

I've combed over the suspension and underside, and the struts show no signs of leaking. The car rides well and is tight. I usually run air pressure at 32-34 psi and check it regularly.

These tires are not high end tires, but have worn like iron despite their cupping.

Is this automatically a sign of suspension issues, or is it just tire design? I have no issue doing a strut job, but dont feel like the car is in dire need.

Thanks!

Ryan

 

[rijndael]

What's the date code on the tire?

 

[Sequoiasoon]

Where and how do you drive? How many years did it take to get to 40k (like @rijndael asked). How much tread is left on all of them?

My father-in-law is all around town. Lots of starts and stops and turns. Some of his wore OK, the Pirelli Scorpion AT was horrible for the weird wear pattern.

 

[Rhill]

What's the date code on the tire?

Tires was built in 2023 and installed shortly after. I forgot to mention that.

 

[Rhill]

Where and how do you drive? How many years did it take to get to 40k (like @rijndael asked). How much tread is left on all of them?

My father-in-law is all around town. Lots of starts and stops and turns. Some of his wore OK, the Pirelli Scorpion AT was horrible for the weird wear pattern.

Thanks guys, we're in Peterborough Ontario Canada. The roads arent great, and we do a fair amount of around town driving.

 

[crashz]

I'm assuming you checked for loose ball joints and tire rod ends? How's your alignment? Tires that scrub even a little can wear unevenly.

 

[Rhill]

I'm assuming you checked for loose ball joints and tire rod ends? How's your alignment? Tires that scrub even a little can wear unevenly.

I'll be back under it now that the garage is cleaned up. Its not showing any signs of noise or wandering, the steering is tight and consistent. I will check though, now that we're through the winter.

It seems to be an issue at all four tires.....almost consistently. Inner edge

 

[JoeDirt41]

Got some pictures of said tires?

 

[zzyzzx]

How's your alignment?

That alone can do it.

 

[Sayjac]

In my experience, tire cupping is 'generally' caused by an out of alignment condition. With that the cause of that condition would need to be determined. If you're lucky just out from normal wear and tear and can be adjusted and brought back to spec. That said, with 100k miles suspension/steering parts, should be thoroughly examined.

 

[Marcozi]

Wearing on the inner edge means that the suspension has too much camber. Or, it could be caused by carrying heavy loads.

 

[IndyIan]

Wearing on the inner edge means that the suspension has too much camber. Or, it could be caused by carrying heavy loads.

Yep, my Focus wagons initially had quite a bit of rear camber, and rear toe-in, and wore the inside edge quite a bit more than the rest of the tire. Just reducing the rear toe-in reduced the wear a lot.

Thanks guys, we're in Peterborough Ontario Canada. The roads arent great, and we do a fair amount of around town driving.

I've used The Alignment Centre in Peterborough, many years ago now, but the fellow just did the alignment I wanted(reduce rear toe-in) so the rear tires weren't fighting each other and making the car unstable on icy roads. At that time they weren't trying to sell parts or tires.
I would go there, with your current tires and see what they come up with. I find our 2018 Outback factory alignment is good for tire wear and the rear toe-in and camber is reasonably straight so the back end is stable. My parents 2015 Forester has too much rear camber and toe in, and the back end is a bit nervous on broken pavement, or icy roads...

 

[LouC]

We had a '98 and currently have a '17. Much as I like Subarus and I really do like them, their wheel bearings are quite weak. Wack a curb one time and they seem to go bad. Had this problem on both, on the '98 what fooled me was the disc brake caliper holding the hub from moving unless it was under the stress of cornering. Remove the rear tires and remove one of the brake calipers. Wire it up so it doesn't hang then temporarily reinstall the wheel/tire and check for play. I was amazed at how much play the bearings on the front of the '98 had, like a 1/8" of movement! So even if the car is aligned with bad wheel bearings, under cornering stress it could be changing. With the calipers in place, you will not feel it.
We also have 3 Jeeps
1998 185,000 miles
2017 151,000 miles
2007 135,000 miles
all still have their original front unit bearings and rear bearings (different design though because they all have live rear axles).

 

[Touring5]

The only time I experienced cupping was from an out of balance tire that lost a lead weight.

 

[D60]

If we're talking wear around the circumference at the inner edge (typically from camber) this is not cupping.

Cupping is like imagine carving out cups in the tread at intervals around the tire. Can also appear as "flat spotting." Cupping is typically from blown shocks/struts that allow the tire to skip down the road.

 

[Rhill]

Thanks guys, I'll take a photo and will report back. Good call on the alignment center! Id forgotten about them!