: One Tire Dead, Do I have to Replace in Pairs?


No Rice
08-05-2007, 09:54 PM
Greetings, I've got stock right-rear 18" tire with 10,000 miles and about 40% wear--6/32" left. The left-rear tire suffered a fatal flat. Do I need to replace both tires in pairs? BTW, I'm going to replace it with an identical stock one and not mix & match.

I've heard stories about wearing out planetary gears and clutch packs if the tires aren't replaced in pairs. So I figure if anyone is going to have a good real-world answer, it will be on this forum. Thanks in advance.

Rob@WretchedMS
08-06-2007, 01:59 AM
It's a good idea to replace them in pairs, (not required, but a good idea)

though if you are going to replace them i would upgrade from the RE040 to the RE050 Pole Position,

JTSnooks
08-06-2007, 04:30 AM
Hard to wear out planetary gears and clutch packs when you don't have any. You're an M6, those parts are in automatic transmissions, although I don't see how have differently-worn tires would affect them. The only thing I could see it affecting is your differential, but can't see a reason why it would hurt it, other than one side having more traction than the other.

TJay74
08-06-2007, 04:34 AM
I think he meant the clutch packs in the diff. If the circumfrence of the tires are not the same you can wear them out, but having one new tire and one old tire on the rear is not enough to do it. It would be no worse than having a properly aired up tire and low tire on there.

I would and always do replace in pairs when a tire dies unless the mileage is low then I replace just the one tire.

Rob@WretchedMS
08-06-2007, 04:44 AM
I believe he was talking about the clutches in the diff,

in theory the tire with more tread will turn slower, thus causing the clutches to work while driving straight, and wearing out.

Real world, the tread would need to be fairly different to do this, but you should replace them in pairs.

J.E.T.
08-06-2007, 06:04 AM
Get two new ones and put 'em on the front.........


JET

ATL_GTO
08-06-2007, 06:22 AM
I have the same problem, I need to replace one of my Potenzas- what about upgrading to a pair of wider tires, like 245s, and putting them on the rear?

J.E.T.
08-06-2007, 06:24 AM
Depends on the quality of the ones you'll be putting on the front. If they're in good shape, no problem. You always want to run your best tires on the front in case of a high speed blow-out.

JET

Rob@WretchedMS
08-06-2007, 06:27 AM
Depends on the quality of the ones you'll be putting on the front. If they're in good shape, no problem. You always want to run your best tires on the front in case of a high speed blow-out.

JET

Can you provide a link to a reputable website/company that states that?

ATL_GTO
08-06-2007, 06:27 AM
Depends on the quality of the ones you'll be putting on the front. If they're in good shape, no problem. You always want to run your best tires on the front in case of a high speed blow-out.

JET

My stock RE040s have most of their tread left, only about 3000 miles of wear. I think I just might do that...

Not to start anything, but I thought you were supposed to have your best/widest tires in the rear on this car?

PreludetoaGTO
08-06-2007, 10:36 AM
I got a fatal flat in one of mine and replaced it. The car started pulling hard. I flipped the tires in the rear to check it, and sure enough, it started pulling in the opposite direction.

So I replaced the other one and everything was fine. There was only 1/8" difference in the treads depth. And this was on stock KDWS's.

Kinda sucked.

No Rice
08-06-2007, 09:44 PM
I think he meant the clutch packs in the diff. If the circumference of the tires are not the same you can wear them out, but having one new tire and one old tire on the rear is not enough to do it. It would be no worse than having a properly aired up tire and low tire on there.

I would and always do replace in pairs when a tire dies unless the mileage is low then I replace just the one tire.

Yes I was worrying about the clutch packs in the diff and and the planet gears. (http://en.wikipedia.org/wiki/Differential_(mechanical_device)) http://upload.wikimedia.org/wikipedia/commons/f/fa/Differential_locked.png

Thanks for all the input from everyone. It looks like I can probably get away with replacing just one tire, but there might be problems. So the low hassle conservative route is to replace both. But that means accepting that one flat cost me around $400 for two tires (sigh)

Anyone got an 18" Bridgestone Potenza RE040 with around 50% wear?