From: hls on

"jim beam" <me(a)privacy.net> wrote in message news:FN-

> tires don't do this on their own, only if there is an underlying cause.

Apparently they do. This vehicle had nothing wrong with it. Shocks were
new and in good condition (Bilsteins), alignment was good, and no worn
suspension parts. That is why I, at first did not rotate. I should have.

>> Took them back to the tire shop (Discount Tire,
>> Lufkin, Texas) and they told me lack of rotation was causing this.
>
> masks the symptoms - doesn't address the cause.
>

There was no mechanical defect...before I took the vehicle for rotation.
Discount
Tire used their Torque Stix, and the rotors warped within a couple of weeks.
Note
that I had had no rotor problems before this happened.


>> Similar happened to our Avalon. Michelins got only 30,000. Replaced them
>> with Kumho' s and am getting much better wear, but noticed at about 10000
>> the ride was deteriorating, noisy, etc. Rotated and it is a-ok for now.
>
> tires with only 50% contact do indeed tend to be quieter!

Im not sure what point you are trying to make. There would have been no
significant
contact difference between the Michelins and the Kumhos. Both were quiet at
first.
The Michelins were still quiet when they wore down to the wear bars.

I do not expect the Kumhos to be as quiet as those particular Michelins,
although
they are very good tires. The Kumhos are a lot harder compound,should last
a long time. Traction is good, but probably not as good as the much softer
Michelins.

Above, I should have said I rotated and had the tires rebalanced. They
returned
them to like new performance.

There is nothing wrong with the alignment or suspension on this Avalon
either.

From: N8N on
On Aug 2, 11:00 am, klu...(a)panix.com (Scott Dorsey) wrote:
> hls <h...(a)nospam.nix> wrote:
>
> >Did you rotate these tires religiously?  That is more important now than
> >ever before.
>
> Is it really?  With modern tires being directional you can only swap them
> front and back when you rotate... does that really make that much of an
> improvement in equalizing wear?

IMHO yes. I can't speak to the OP's car, but my experiences with FWD
Impalas (used as company cars at my employer for at least the last 5
years) is that they chew up the outsides of the front tires at a
shocking rate, and in fact, they probably ought to be rotated more
often than even the most conscientious people do (every 7000 miles,
which is when we get the oil changed.)

I do run my tires at a little bit higher than recommended pressure
(33-35 PSI vs. 30 PSI) and that seems to help a little but tire wear
is still not great.

nate
From: Steve W. on
N8N wrote:
> On Aug 2, 11:00 am, klu...(a)panix.com (Scott Dorsey) wrote:
>> hls <h...(a)nospam.nix> wrote:
>>
>>> Did you rotate these tires religiously? That is more important now than
>>> ever before.
>> Is it really? With modern tires being directional you can only swap them
>> front and back when you rotate... does that really make that much of an
>> improvement in equalizing wear?
>
> IMHO yes. I can't speak to the OP's car, but my experiences with FWD
> Impalas (used as company cars at my employer for at least the last 5
> years) is that they chew up the outsides of the front tires at a
> shocking rate, and in fact, they probably ought to be rotated more
> often than even the most conscientious people do (every 7000 miles,
> which is when we get the oil changed.)
>
> I do run my tires at a little bit higher than recommended pressure
> (33-35 PSI vs. 30 PSI) and that seems to help a little but tire wear
> is still not great.
>
> nate

VERY common problem with all FWD vehicles. With a RWD vehicle the rear
tires pushed the vehicle and ran in a straight line with some side
loading through corners. Front steered the vehicle with angular loading
due to Ackerman geometry and loading through turns.

On a FWD vehicle the rear tires do little other than act as trailer
tires supporting the rear of the vehicle. About the only load is minor
sidewall loading in corners.
BUT the front tires are getting beat to death, They have to drag around
all the weight, steer the vehicle, provide 80% of the braking as well as
handle the vibration and torque inputs from the engine.

In the fleet vehicles I used to drive the company never wanted the tires
rotated. On the Caravans we ran it was very common to still have factory
tires on the rear at 100K miles, with a lot of tread left, and have
chewed through at least 4 sets of front tires.

As for modern tires being directional, Only if they are performance
tires with directional tread is that the case. Common tires can handle
rotational changes easily, UNLESS they have been subjected to serious
abuse (burnouts, slamming on the brakes and the like) Then you may get
the plies to shift enough the reversing the rotation causes problems.

--
Steve W.
(\___/)
(='.'=)
(")_(")
From: jim beam on
On 08/02/2010 11:59 AM, N8N wrote:
> On Aug 2, 11:00�am, klu...(a)panix.com (Scott Dorsey) wrote:
>> hls<h...(a)nospam.nix> wrote:
>>
>>> Did you rotate these tires religiously? �That is more important now than
>>> ever before.
>>
>> Is it really? �With modern tires being directional you can only swap them
>> front and back when you rotate... does that really make that much of an
>> improvement in equalizing wear?
>
> IMHO yes. I can't speak to the OP's car, but my experiences with FWD
> Impalas (used as company cars at my employer for at least the last 5
> years) is that they chew up the outsides of the front tires at a
> shocking rate, and in fact, they probably ought to be rotated more
> often than even the most conscientious people do (every 7000 miles,
> which is when we get the oil changed.)

if these tires are not running on the center line, these vehicles need
to be realigned. one of the problems with fwd macphersons, especially
ones with sloppy longitudinal positioning like the impala, is that when
driven hard [fleet vehicles], the drive torque has an effect on
alignment. the factory setting is an average for "average" driving. if
your fleet's "average" driving differs from that, they need to be
aligned with slightly more toe out to compensate for the actual loads.


>
> I do run my tires at a little bit higher than recommended pressure
> (33-35 PSI vs. 30 PSI) and that seems to help a little but tire wear
> is still not great.
>
> nate


--
nomina rutrum rutrum
From: Clive on
In message <FN-dnQcGYqxhncrRnZ2dnUVZ_gKdnZ2d(a)speakeasy.net>, jim beam
<me(a)privacy.net> writes
>nomina rutrum rutrum
I've just looked up your sig in a Latin dictionary.
Nomina = Name
Rutrum = Shovel, Spade or trowel. What does it mean when it's combined
as it is?
--
Clive