Uneven tyre wear [but not the usual]

I have a 2005 Corsa SXi which has done 43,000 miles. At 36,000 I bought two
new tyres to replace the worn out fronts [first replacements]. These wheels
with the new tyres were put on to the rear of the car and the rear wheels
put on the front. Tyres are Pirelli P6000, same as originals. Around about
the same time the car was put in to have a noisy front offside wheel bearing
investigated, both noise and play, the nearside one was replaced. Car goes
back in with the noise still there, they replace the front offside wheel
bearing this time, noise now cured. When I bought the two new tyres I also
had tyre sealant installed [car is LPG so no spare tyre etc] since then
noise and vibration gradually got worse and car was taken back in. This is
the main bit, the old tyres, now on the front, had uneven wear, spin one of
the tyres and there depression of up to 3mm along the inner half of the tyre
for about quarter of the circumference, the other has between 1 and 2 mm of
a similar depression, almost what you would expect if the car had been left
standing for a long period, but the car is used daily, mainly motorways and
usually around 60 - 70. Someone has suggested to me that it could be a case
of the original tyres not being seated in the bead properly when new and
deflating the tyre to put the sealant in and then re-inflating it has
altered how the tyre was sitting in the bead. Finally to check the rest of
the set up I swapped with a neighbour's Corsa's wheels: -
my car with his wheels running smooth but severe juddering under braking,
telling me my discs are goosed,
his car with my wheels running relative smoothly but with a bit of vibration
[tyres were put on with the bad ones on the rear so did not get a chance to
try them on the front wheels].
Long winded post but hopefully lets you get the picture, and looking for
suggestions.

Thanks
Ian

 

well the severe judder on changed of wheels could be just balancing./toe in

as for yours, i wonder if they were not inflated correctly/in time before
the sealant set?

if you deflate the tyres [car raised] do they look the proper shape
i had a very bad rumble on one like that
let the air out, and it was almost flat [deformed] when not under pressure.

mike

 

You put the tyre sealant stuff in as a preventative measure?????
Shudder under braking isn't always warped discs. In fact, I've never
come across a case when it was.

 

I know nothing about these cars, but have seen this type of wear on
commercial vehicle tyres. I can't say for definite the cause but believe
ineffectual shock absorbers had something to do with it.

Roger R

 

Thanks Mike, I will try deflating the tyres to what they are like not under
pressure, just strange that everything has happened over a short period of
time but then I suppose a lot was changed with the front to back tyre swap,
sealant and the wheel bearings.

Ian

 

Hi adder

Sealant was put in as a preventative measure. The car has no spare and
comes with an aerosol can of sealant/inflator for use in emergencies. The
shudder is only noticeable under braking and at the outset was probably
hidden by the unevenly worn tyres. Mike has suggested that I check the tyre
when deflated to see if the deformation is still there and that will be the
next step.

Ian

 

Hi Roger

Another good point, I will check the shockers too, though there was no sign
of leakage notices when I was swapping wheels over.

Ian

 

Should have added that the sealant does not set, but spreads itself round
the inner of the tyre in the tread area so that as soon as a puncture occurs
it will seal the hole [providing it is not too large] and the driver will
probably never notice. When the sealant was put in you are instructed to
drive at 30 mph for something like 5 miles to allow the sealant to spread
over the inside of the tyre. If the car is left for anything over a week
then it is recommended that you carry out the same "bedding in" procedure.

I have just had a look at the company website and it states that "we must
point out that some vibration may appear if your vehicle's wheels are not
properly balanced prior to installation of the product". What I need to do
now is check the sealant paperwork I got from the garage and make sure that
is also on it. I don't recall the original rears being re-balanced prior to
the sealant going in.

Ian

 

I'd say that using this stuff is not a good idea - adds weight,
unbalances the tyres etc and makes it more difficult when you come to
get new tyres.

I've had cars with all sorts of knackered suspension etc and have
never had this problem.

 

I have, curiously after some brush wielding insurance chosen monkeys had
repaired some accident damage, which included rebuilding front nearside
suspension and the car was stopped for a few weeks.

Totally cured by new pads and disks.

Probably totally OT. but there we are.

Tom