39RN

2014 IS350 Fsport. I replaced the stocks at 29K Miles with Pilot SS AS+. 8K miles on the Pilots and now the car sounds like a tank driving down the road. Dealer told me today that it was extreme cupping and that I need to buy 4 new tires and get it aligned. He said this was the best thing I could do to trouble shoot why it is happening so quickly. I said that is an expensive trouble shoot experiment!! They then proceeded to tell me that until I do that there is no reason for them to inspect or consider shocks or struts, which I requested.

Any advice on where I should start? The tires look good to me, but I have no clue what I am looking for. I hate to purchase another set and "give it a try"!

I also feel nothing in the steering that would tell me something is out of alignment. Tracks strait as the day I bought it, no shake or wiggle.

Thanks in advance for any suggestions.

(Pictures) Front DR/Fr Pass/Rear Dr/Rear Pass

Olasek

Unless you provide 3D images - nothing can be said from those fragmentary 2D images.

Sasnuke

It's hard to see "cupping" in a photograph.
The Driver's front tire does look to be feathering more than cupping...but once again, hard to tell from a photo.
The rear tires seem to be worn down the center a lot more.
I'm going to assume your 350 is RWD.

What pressures do you run in the tires?
Did you do an alignment when you replaced the tires last time?

To be honest, an alignment should be done anytime you install new tires. When you think about how often you replace tires, that's an alignment every few years.
I guarantee that someone on here is going to say the exact opposite...but I've never replaced tires for cupping, feathering, or any other alignment related issue...only when the tire has simply worn out.

Doing an alignment with the tires you have now isn't going to help because they are definitely worn uneven.
Really your options are to drive them til they wear out completely, replace all 4 and do an alignment...or replace them now and do an alignment.
The fix, either way, is the same...just whether you do it now or later.

39RN

Thanks Sasnuke. Your suggestion aligns with the dealer. Sorry for the crappy 2D pics but looking at them I was just scratching my head because there is sooo much tread left. But I guess a little out of whack will make it sound like a tank!

I did not get an alignment as I was at 29K miles with no sign of needing an alignment. I can agree that it should just be one of those things you do. Live and learn. If that was the reason... it was an expensive mistake.

AWD

jkonquer

how many miles you have on your new tires? cupping doesn't happen to brand new tires. It takes over time and it generally happens when the wheels were unbalanced. Best way to tell if you have a cupping is rub your hand around the tire for uneven heights in the tread.

I just replaced mine as well with Michelin PSS and were little loud in the beginning but it went away after about 1000 miles.

39RN

Started noticing the loud road noise around 8k on the tires. Have 10 on them now.

jkonquer

So the dealer confirmed that it showed cupping on all four tires? Like I said before cupping comes from either unbalanced wheels or bad shocks.

It sounds to me that the tires shop might not have balanced the wheels when mounting the tires and I highly doubt all your shocks are blown. An alignment should be done when installing new tires like sasnuke said, but unless it has "extreme" toe setting on all four corners it shouldn't be the reason why you have this issue.

Couple things I can suggest are to go back to the tire shop where you purchased the tire from and request a refund for faulty installation, unless you knew that they weren't going to balance the tires. Or call Michelin, all of their tires covered by warranty and they should at least give you an prorated tire cost. (ie Michelin A/S is covered for 40k and they should cover up to 30k since you are at 10k)

Also, from the look of it, you have cupping on the rears tires. Can't really tell from the picture.

Olasek

This is a myth.
Alignment should be done when previous tires wear unevenly or you need alignment for other reasons (long time since last alignment, suspension issues, etc) but new tires alone don't automatically call for alignment. Where I live people may put snow tires for winter, then switch to summer tires and nobody is doing alignment when swapping tires, no reputable tire shop should make such automatic recommendation.

jkonquer

Read the rest.

Around 20-40k mile is a good time do an alignment, which happens to be the around the time when you switch tires. And to ensure that your alignment is not off and to help wear the tires evenly. It is a Pretty Good idea.

Sasnuke

I think there may be a misunderstanding here...
When installing brand new tires...then yes, I would recommend to check the alignment.
When swapping tires due to change in seasons...then no, alignment is not needed.

Not everyone can easily identify when tires are wearing unevenly or even feathering, so if you're waiting for obvious signs of uneven wear, then it's probably too late by then.
I guarantee that if you randomly pulled 10 vehicles off the road and put them on a rack that 9 of them are out of alignment, even if it's just a slight Toe adjustment.
I like to think that alignments are preventative maintenance rather than reactive maintenance, meaning, if you need to do the alignment because of uneven tire wear, then its too late, should have done it before to prevent the uneven wear and ruining a set of tires.

39RN

Yes. All four tires. I appreciate the advice. I Just looked and you can see where they took the old weights off and put new ones on inside the rim. SO it looks like they attempted to balance them.

jkonquer

Then it could also be overinflated tires if the cupping is in the middle of the tires.

brendanf

Its always been my understanding that cupping is the result of bad shocks.

If the tires were out of balance you would feel a shimmy in the steering wheel and you haven't reported that.

It certainly won't hurt to get an alignment just to rule that out, and semi worse case get the tires rotated so the wear is done evenly. I'm not sure if your tires are directional and if they are that means physically swapping the rubber from rim to rim to maintain the direction orientation, which would cost a few $$.

39RN

There is no shimmy in the steering at all. I have never noticed any difference in steering since the day I bought the car. I mentioned the shocks to the dealer as a potential cause and they dismissed it immediately and went straight to the alignment. Not sure how I would get them to check the shocks, is it a simple procedure for them to test the shocks?

Sasnuke

Aside from actually removing a shock, there are two basic tests that you can perform...you can even do them yourself.
First is visual inspection...lift the vehicle off the ground (or one wheel at a time) until the suspension is completely hanging (or wheels off the ground).
The shocks will be at their maximum extension and you can see if any are leaking where the shock piston goes into the shock body...this would be somewhere just above the center of the shock, roughly.
If it's leaking, time to replace.
Second is a bounce test...with the vehicle on level ground, or as level as you can find it, bounce each corner of the vehicle as hard as you reasonable can.
What you're looking for is the vehicle to bounce back and stop. So you push down a couple times to get a rhythm going and then let go when you're on a down stroke.
You're looking to see the car comes back up and then go down just a tad, and stop. If it bounces multiple times on it's own, that shock at that corner is no good.
Lastly a road test to confirm shock operation. Drive the vehicle, preferably at highway speeds. Note any time you hit a significant bump in the road.
Shocks that are not functioning properly won't be able to stabilize a wheel that hits a significant bump. The wheel will continue to hop on its own until it finally stops...which likely it won't because you'll hit another bump and that just restarts the hopping.
Driving beside a vehicle that this is happening to is quite comical.
The hopping translates into a vibration for the driver...if a front wheel is hopping the steering wheel will vibrate...if a back wheel is hopping you'll feel a vibration in the lap of your seat (basically in your butt).

If you had the shocks out, the easiest way to check them (aside from a visible leak) is to push the piston all the way down.
If it doesn't come back up, the shock is done.
If it comes up slowly at a moderate pace to full extension, the shock is fine.
If it comes up really really slow and does reach maximum extension, the shock is done.