Swaying with new rear tires.

[Count Mackula]

The problem: I have a 21 3.0 with stock wheels. At 19K miles, I noticed the rear tires wearing out on the inner part of the tires. I decided to replace them (JUST THE REAR TIRES). I plan on replacing all wheels with TE37s with new meats and wider wheels in the near future. So I just replaced the rear tires for the time being with Firestone INDY. Had them mounted and balanced.
So upon driving the car, I took it on the freeway and the fucking car started swaying on me. I remember reading that a bunch of people had the same problem with other tires. Figured they were exaggerating. But the damn car is terrifying it drive while it’s swaying. The traction control would kick on at 80 MPH on turns you would NEVER think it would ON FREEWAYS.

I figured that the car would eventually straighten out and stop after a few hundred miles. But I want to know why. I googled it and read a bunch of threads and etc. Several people have mentioned that it’s lube of some sort that needs to wear off and etc. (which I doubt)

Any idea what it might be? And how did you guys solve this issue? I’ve had several RWD cars and replaced ONLY the rear tires on many of them and never had this issue. What’s the reasoning of this?

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[suicidaleggroll]

Have you ever done an alignment on the car? Did you go into the infotainment system and tell it you were running custom tires?

 

[Count Mackula]

Have you ever done an alignment on the car? Did you go into the infotainment system and tell it you were running custom tires?

Never did the alignment since it’s the same tire and wheel size and stock. Never had a problem with past cars when I just replaced the tire with no alignment. The tire psi is about 40 for all four (it was has as hell today).

I have informed the car of the new tires and the problem still exists.

I just reduced the PSI to 33 in the rears and will see if that helps. I’ll give it a go tomorrow and will report back here.

Keep in mind the fronts still have 19K miles on them and the stock Dunlops. The rear are about 75 miles now Bridgestone. I’m certain it will stop in the next few hundred miles. But I’d like to get the bottom of this so I can avoid this issue in the future.

 

[suicidaleggroll]

The alignment isn’t because of the new tires, it’s because these cars come with garbage alignments from the factory. An aftermarket alignment is pretty much required just to bring the car to OEM specs. It could be that the instability was always there, it just wasn’t as pronounced with the PSS as with these tires.

 

[Count Mackula]

The alignment isn’t because of the new tires, it’s because these cars come with garbage alignments from the factory. An aftermarket alignment is pretty much required just to bring the car to OEM specs. It could be that the instability was always there, it just wasn’t as pronounced with the PSS as with these tires.

OOOOHHHH!! I had no clue.
Yeah, I noticed the inner part of my rear tires were wearing out MUCH sooner than the rest of the tire. That sucks. I live in hi desert in California. Anybody know a good alignment shop out here?
What does “PSS” mean?

 

[Bundy]

Pilot Super Sport

 

[Loco38SUP]

It almost sounds like the mismatch on the tire brand and tread wear are causing it. I would start with an alignment and if possible 2 new matching fronts.

-RJM

 

[Count Mackula]

Gotcha. That sucks. Thanks guys.

 

[Heavy Foot]

I have the same issue with the sway. I just installed 305 30 r19 pilot sport cup 2's. Yup, it's scary, especially on wet pavement

 

[Count Mackula]

I have the same issue with the sway. I just installed 305 30 r19 pilot sport cup 2's. Yup, it's scary, especially on wet pavement

Oh damn… did you get it fixed? So these clowns that changed the tires inflated it to +40 PSI and I dropped it down to low-mid 30s and it didn’t sway anywhere near as bad. Were your tires overinflated as well?

 

[jtsang25]

Never did the alignment since it’s the same tire and wheel size and stock. Never had a problem with past cars when I just replaced the tire with no alignment. The tire psi is about 40 for all four (it was has as hell today).

I have informed the car of the new tires and the problem still exists.

I just reduced the PSI to 33 in the rears and will see if that helps. I’ll give it a go tomorrow and will report back here.

Keep in mind the fronts still have 19K miles on them and the stock Dunlops. The rear are about 75 miles now Bridgestone. I’m certain it will stop in the next few hundred miles. But I’d like to get the bottom of this so I can avoid this issue in the future.

Why do you have "stock" Dunlops. When stock tires are suppose to be Michelin pilot super sports

 

[OneTimeAccount]

You said you have the Firestone Indy tires? As in the Indy500 Tires? That's what I have as my daily street tire on stock wheels and yes, they definitely sway a lot when new but get a little better over time as they wear in. I had the same issue. Also, more than spec negative camber and higher PSI exaggerates the issue.

If the inside of your tires are wearing considerably faster than the rest of the tire, that means excessive toe, camber, or both. Highly recommend an alignment. You shouldn't be having that much tire wear on the inside of your tire from just daily driving it.

 

[puzzled]

Brand new tires usually need to be broken in.. ?

It's also good to look left and right before crossing the street.

..I sound like a fortune cookie.

 

[Count Mackula]

You said you have the Firestone Indy tires? As in the Indy500 Tires? That's what I have as my daily street tire on stock wheels and yes, they definitely sway a lot when new but get a little better over time as they wear in. I had the same issue. Also, more than spec negative camber and higher PSI exaggerates the issue.

If the inside of your tires are wearing considerably faster than the rest of the tire, that means excessive toe, camber, or both. Highly recommend an alignment. You shouldn't be having that much tire wear on the inside of your tire from just daily driving it.

Yes, that is correct. I may have messed the names of tires earlier. But I have the Firestone Indy 500.
sounds like I’m just gonna have to get an alignment. :-/
I dropped the psi down to 33 and it seems to have fixed the issue for now. I know it’ll break in eventually and it’ll be fine. Just scary as hell right now.

 

[OneTimeAccount]

Yes, that is correct. I may have messed the names of tires earlier. But I have the Firestone Indy 500.
sounds like I’m just gonna have to get an alignment. :-/
I dropped the psi down to 33 and it seems to have fixed the issue for now. I know it’ll break in eventually and it’ll be fine. Just scary as hell right now.

Yeah, it's always best to check tire pressures after they're mounted. Shops always over inflate them, usually to 40+ PSI and that makes them feel scary on the highway.

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