Wierd Marks Appearing On Tires

[PointyWombat]

Hello,
The line in the photo appeared a few months ago on the rear tires of my 2012 Silverado 3500 SRW. They were only on the rear. I rotated the tires about 3000km ago, and now these marks have started to appear on the rear tires again. Since rotating the tires, i have towed my 5er about 500 kms. The tires are Cooper Discoverer X/T4 with ~40000 km on them.


Would anyone have any insite on what these marks may be the result of? They are not rubbing or anything like that. Also, the marks are basically the same on both sides.

Thanks,
PW

[csuder99]

Couple of Q: Did the marks go away on the tires that were switched to the front ? Do the marks appear on the rear tires only after towing ? Stock tire size ?

Still looks to me like the tires get marked by some sort of rubbing. With the 5er on the rear axle it rides lower, any chance there is something in the top of the wheel well that might occasionally make contact with the tires when compressing the suspension ?

[wandering1]

So what did the tire dealer tell you
????

[1st-tt2018]

That looks like a defect that is coming out with heat. Zooming in on the photo, each tread has a start and stop just before the edge of each lug and they are the same on each one. That would concern me too. They should be replaced by the tire dealer under treadwear warranty.

[kdauto]

Originally Posted by PointyWombat

Hello,
The line in the photo appeared a few months ago on the rear tires of my 2012 Silverado 3500 SRW. They were only on the rear. I rotated the tires about 3000km ago, and now these marks have started to appear on the rear tires again. Since rotating the tires, i have towed my 5er about 500 kms. The tires are Cooper Discoverer X/T4 with ~40000 km on them.


Would anyone have any insite on what these marks may be the result of? They are not rubbing or anything like that. Also, the marks are basically the same on both sides.

Thanks,
PW

Which lines are you referring to exactly? The line that's dead center is part of the tread design. If you're talking about the very slight cracking that surrounds some of the tread blocks that is what is commonly referred to as "dry rot"...cracking basically.

Can you give us the date code of the tires? Look on the sidewalls, can be mounted either in or outside. Look for a long number stamped that starts with "DOT". At the end of the number there's 4 numbers, let's pretend it ends with 3415. That would mean that tire has been produced 34th week of 2015. If those are the original tires made in 2011 or 2012 they are way overdue. Dry rotting is something to be looked at seriously. That one looks to be starting but many more pics are needed to evaluate. If in doubt, replace them.

[Mtn. Lion]

Email Cooper Tire and ask them.


Coopers photo of that tire new doesn't have the seam looking line. I wouldn't haul a load and/or speed until you hear back from them. The tire looks close to being done, but there is certainly life left so they may give you a discount on a new set. If you want that.

[Ljwt330]

My opinion, not an expert.

Close up of the photo clearly shows the line to be from construction of the tire, not from something scraping from the outside. A search of used tires of the same model show the same or similar line, sometimes. There doesn’t seem to be a consistency in it’s presence, except it’s only in used treads.

This site shows some used tires for sale. https://www.kijiji.ca/v-pneus-jantes...ationFlag=true

Look at some ads and you will see the same thing. I believe it is not a defect but a result of the mold used in some tires.

[Ljwt330]

Here are some photos of used tires of the same make and model, taken from the site I posted. You can clearly see the line in the first photo, and if you look closely, in the other two as well.

[NevadaNick]

I have 4 new Cooper tires sitting in the garage that are going on my truck tomorrow, they all have the line in the center tread. Its just part of the mold.

[wingnut60]

Yes, a mold mark.

[PointyWombat]

Originally Posted by csuder99

Couple of Q: Did the marks go away on the tires that were switched to the front ? Do the marks appear on the rear tires only after towing ? Stock tire size ?

The marks on the tires moved to the front remain. Marks appeared on the rear after rotation. I've used the truck a couple times to tow after the rotation, and notice subtle marks starting to develop. Tires are stock size.

Still looks to me like the tires get marked by some sort of rubbing. With the 5er on the rear axle it rides lower, any chance there is something in the top of the wheel well that might occasionally make contact with the tires when compressing the suspension ?

There is absolutely nothing rubbing on the tires. There is plenty of room around the entire tire when loaded with the 5er.

Regards

PW

[PointyWombat]

Originally Posted by Ljwt330

Here are some photos of used tires of the same make and model, taken from the site I posted. You can clearly see the line in the first photo, and if you look closely, in the other two as well.

This certainly is interesting. My concern is that these marks were never there earlier in the tires life. They only began to appear recently. Also, a closer view shows what appears to be deteriorating rubber...

I have sent an email and photo to Cooper for their comments.

[PointyWombat]

Originally Posted by kdauto

Which lines are you referring to exactly? The line that's dead center is part of the tread design. If you're talking about the very slight cracking that surrounds some of the tread blocks that is what is commonly referred to as "dry rot"...cracking basically.

Can you give us the date code of the tires? Look on the sidewalls, can be mounted either in or outside. Look for a long number stamped that starts with "DOT". At the end of the number there's 4 numbers, let's pretend it ends with 3415. That would mean that tire has been produced 34th week of 2015. If those are the original tires made in 2011 or 2012 they are way overdue. Dry rotting is something to be looked at seriously. That one looks to be starting but many more pics are needed to evaluate. If in doubt, replace them.

Date code is 1915. I bought them June 2015

Regards,
PW

[PointyWombat]

Originally Posted by wandering1

So what did the tire dealer tell you
????

I've been parked and camped for the past couple weeks but plan to visit the dealer when I return from this trip in a few more days. I'm also waiting for word from Cooper.