After only 35,000 miles of pretty good driving, I had to replace my Cooper Discoverer A/Ts on short notice because the sidewalls had started to crack.

When I had the truck in for service, the tech noticed the sidewalls cracking along the circumference of the tire (all the way around, on all 6 tires) in between the sidewall and the tread.

Apparently this can quickly lead to tread separation, so Cooper told me to go to a dealer right away and get it inspected. Sure enough, they decided that the tires had to go.

With some more research, this is a common problem with Coopers and there has been a class action lawsuit that lead to an extended warranty for tread separation as well as several recalls.

I found a Cooper dealer who did the adjustment and installed 6 Toyo Open Country A/Ts.

Hopefully they will work better.

If you have Coopers, take a good look for sidewall cracks ...

geez, that would have been a bloody mess. anything on the discoverer s/t's?- or is it all coop's that this is a problem? i have about 30,000 on them, but have'nt noticed any cracking (yet) 2 good, hard michigan winters, and 70psi. i will really keep an eye on them now. do you have any info as to how you contacted cooper to discover (pardon the pun)? thanx-:t

I think there is something about it on the Cooper Tire web site.

www.coopertire.com

specifically, you can get an "enhanced warranty" ???

http://www.coopertire.com/us/en/warranty.asp

and here is some more information from the web site regarding the "enhanced warranty". It apparently will give the owner of a tire produced from 1985 to 2001 a replacment tire in the event of an "adjustable separation", whatever that is.

http://www.coopertire.com/us/en/corporate/news/news-release.asp?id=252

Thanks for the info on the tires. I had the A/T's on another truck and never noticed anything wrong with them. I have never heard of any problems before about Cooper tires, unlike the Firestones.

Thanks for the info on the tires. I had the A/T's on another truck and never noticed anything wrong with them. I have never heard of any problems before about Cooper tires, unlike the Firestones.
I was shocked too. But after a few google searches, I am not alone in experiencing this problem.

I got 35,000 good miles on the Coopers without as much as a flat. Not bad, but 50,000 would have been better.

So far, the Toyo's ride a little better but with more road noise and vibration. Could just be the feeling of new tires with deeper tread though.