Tire cupping - DuraTracs!

[DC runner]

This continues to point to the traditional culprit. Suspension/front end. I still think, barring other evidence, shocks are the culprit in cupping.

 

[maclean216]

Can you post pics of the tires?

 

[yotaboy510]

This happened to my friends sequoia, after changing shocks and new tires. No more problem and it's been 20k miles already

 

[Big John]

If you are not running 60 to 75 psi, then the E rated tires are causing your problems.

If you want to run lower pressures, you will need to add about 1000 pounds of ballast to your ride.

Ummm… The inflation rates are based on weight. There is no need to run 75 lbs on a 5k lb car. I will wear out the centers.

 

[jonwilly2]

my shocks are good and had a issue like this and the shop my dad took it to reused the bushings so they eventually gave out that was my problem.

 

[jksmyers]

Looks like I caused some controversy. First time to do that on this particular forum. To answer a couple of the questions that have been raised....

This was not an issue with my last set of tires. (Stock Goodyear Wranglers) The wear was nice and even when I dumped them - and it was time to change them. Very little tread left.

I'm still running the stock shocks/springs - at least as far as I know. I've only had it for a little over a year.

And about the TRE's, I checked for play a couple weeks ago when I had it up on jack stands changing the brake pads. Felt solid as a rock. Not saying that proves anything, but there was no obvious play.

Lastly, I increased the pressure to 45 psi before leaving for work this morning. Actually felt better.

And thanks everyone for trying to help diagnose the problem. Nothing I said above will likely help in the debate much. Regardless, I like hearing all the different theories, and I'm honestly going to use this as an excuse to upgrade the suspension - which I've been wanting to do for a long time.

*Edit - and as for pics of the tires, I'll try to get one or two tomorrow. Might be hard to take one that shows it well.

 

[Singtoe]

Your truck is too light for e-rated tires. No 4wd, no plate bumpers, no skid plates.

Putting stiffer struts and springs will make you truck ride like a steam roller.

I am assuming that the old tires weren't E-rated and they wore just fine.

In my opinion, run higher tire pressures to keep from cupping. Tires might be damaged already if the cupping is deep enough. Might have to buy two more tires.

Fwiw, I don't want to piss any body off but I have seen it too many times and tire pressure seams to be the only fix.

Know, for those that have E-rated tires and running 32 psi - good for you, consider your self fortunate. The tire gods have blessed you with smooth harmonics and perfectly toes

 

[IanB]

For those suggesting struts as the culprit, can anyone explain to me how worn struts could cause the tires to cup? My understanding is that cupping occurs when the tire rides on the outside edges of the tread rather than evenly across the surface, and this is largely due to under-pressurized tires.

I also feel that 10 ply (E-rated) tires will require more pressure to effect a change on the shape of the tire than 6 ply (C rated) tires would, hence why you run roughly 36psi on a c-ply for example, and 45+ on an e-ply for the same size tire, on the same vehicle to get even treadwear.

To the OP: now that you have upped the tire pressure, try using sidewalk chalk to mark the tread surface, then drive a bit and see what wears off, and adjust until you get even tire wear. Hopefully they aren't ruined. It's going to ride stiffer with the proper pressure in them, as they are 10 ply tires afterall.

 

[theizzardking]

For those suggesting struts as the culprit, can anyone explain to me how worn struts could cause the tires to cup? My understanding is that cupping occurs when the tire rides on the outside edges of the tread rather than evenly across the surface, and this is largely due to under-pressurized tires.

I also feel that 10 ply (E-rated) tires will require more pressure to effect a change on the shape of the tire than 6 ply (C rated) tires would, hence why you run roughly 36psi on a c-ply for example, and 45+ on an e-ply for the same size tire, on the same vehicle to get even treadwear.

To the OP: now that you have upped the tire pressure, try using sidewalk chalk to mark the tread surface, then drive a bit and see what wears off, and adjust until you get even tire wear. Hopefully they aren't ruined. It's going to ride stiffer with the proper pressure in them, as they are 10 ply tires afterall.

shoulder cupping is almost 100% caused by a suspension components, if the tire was under inflated the tire would be cupped on both the inside and outside of the tire, basically from the tire riding on the high pressure point in the tire on the middle ......

the cupping on the shoulder and bad shocks usually mentioned together because the bad shocks cause the tire to hop skip and jump across the road , and thats got to do something to the tires right? lol



he needs to get his alignment checked again just to be sure, after that i would assume shocks and coils provided everything is still in alignment when he goes back, if it's off again he has some slop some where in the alignment system

a pretty good lay out of wear patterns for tires
http://www.procarcare.com/includes/content/resourcecenter/encyclopedia/ch25/25readtirewear.html

 

[IanB]

shoulder cupping is almost 100% caused by a suspension components, if the tire was under inflated the tire would be cupped on both the inside and outside of the tire, basically from the tire riding on the high pressure point in the tire on the middle ......

Did I miss where he said the tires were wearing only on the outer shoulders and not both outside edges of the tire?

Edit: I see, cupping means something other than what I've always heard it used as. I guess we need some clarification as to what wear the tires are showing, pics would help.

 

[ALBPM]

Looks like I caused some controversy. First time to do that on this particular forum. To answer a couple of the questions that have been raised....

I'm still running the stock shocks/springs - at least as far as I know. I've only had it for a little over a year.

Lastly, I increased the pressure to 45 psi before leaving for work this morning. Actually felt better.
.

The original stock shocks and coils on a 2000 runner....
Here's the problem with running the "E" weight tires.
The stock shocks aren't valved for running heavy tires plus they must be really worn out by now.

Back the tire pressure for the front tires down to 40 psi and the rear down to 38psi.

Look into getting some better shocks such as the Bilstein 5100s or some OMEs along with new coils .

I just put some 265/75/16 "E" weight Dueler Revos on my wife's 2WD Tacoma
Pre-Runner along with Bilstein 5100 shocks. 39psi in the Front tires and 37 psi in the rear tires. Her truck is lighter than my Runner.

She loves the way it rides and handles. The "E" weight tires replaced a set of Michelin LTX M/S "C" weight tires.

I ran 265/75/16 "E" weight Revos on my 2002 Runner at 39psi in the front and 37psi in the rear for 81,500 miles before I replaced them with 285 "E"s.

I still had enough tread to go another year or more...but at 8 years I decided it would be safer to get new tires. :thumb3: plus I wanted 285s

 

[BigFishAllDay]

You know what's funny about his thread... The OP doesn't even give a rats ass. He just wants a lift, and his mind is already made up. Meanwhile everyone sits around arguing about why his tires are cupping.... Me?

 

[Singtoe]

You know what's funny about his thread... The OP doesn't even give a rats ass. He just wants a lift, and his mind is already made up. Meanwhile everyone sits around arguing about why his tires are cupping.... Me?

Was it with another dude?

:lmao:

 

[Singtoe]

Obamma says inflate your tires.:lookout:

 

[jksmyers]

You guys are nutz! And BigFish - I do give a rats ass.

I love my tires and they weren't cheap. I want to do whatever I have to do to save them. In hindsight I would not have settled for the e-rated. That's all they had on hand. But now I have them and I want to save them. I also realize I'm rationalizing the purchase of some toys, but I can buy new shocks/springs, TRE's, LBJ's, etc. and still not equal what I paid for those damn tires. And all that stuff is 11 years old, so it's probably time anyway. (Rationalization part over now.)

As for the "cupping" term, I'm using it because that's the term the tire guy used when they were balanced the other day. I tried to get a pic with my phone, but it sucked. Basically it's a more-or-less diagonal pattern across the tire with certain individual tread blocks being scalloped/cupped. Most of the cupping on the blocks is actually in the middle pattern of the tire - not the outside. It's not too bad at this point, but enough to cause a rythmic "humming" on the road. It happened only to the fronts, which have now been moved to the rear. That's why I want to move fast on this to keep from messing up the good ones on the front now.

 

[maclean216]

You guys are nutz! And BigFish - I do give a rats ass.

I love my tires and they weren't cheap. I want to do whatever I have to do to save them. In hindsight I would not have settled for the e-rated. That's all they had on hand. But now I have them and I want to save them. I also realize I'm rationalizing the purchase of some toys, but I can buy new shocks/springs, TRE's, LBJ's, etc. and still not equal what I paid for those damn tires. And all that stuff is 11 years old, so it's probably time anyway. (Rationalization part over now.)

As for the "cupping" term, I'm using it because that's the term the tire guy used when they were balanced the other day. I tried to get a pic with my phone, but it sucked. Basically it's a more-or-less diagonal pattern across the tire with certain individual tread blocks being scalloped/cupped. Most of the cupping on the blocks is actually in the middle pattern of the tire - not the outside. It's not too bad at this point, but enough to cause a rythmic "humming" on the road. It happened only to the fronts, which have now been moved to the rear. That's why I want to move fast on this to keep from messing up the good ones on the front now.

How often are you rotating your tires?

 

[BigFishAllDay]

Was it with another dude?

:lmao:

No, I invited your sister over.:boink:

In case you need further explanation... click > http://www.nbc.com/saturday-night-live/video/snl-digital-short-i-just-had-sex/1265873

 

[jksmyers]

How often are you rotating your tires?

I just rotated them for the first time. I'd put about 8K on them. So not often enough, apparently.

 

[sportscarfan]

I said this in the "Do you let tire shops/service shops drive your vehicle?" thread earlier...seems relevant to this one.

I had a balance issue with my Duratrac 285's after about 1000 miles. At close to 60mph, it had the shakes pretty bad. Soon after, doing some routine maintenance, I decided to rotate the tires in an X pattern. Like magic, the major shakes at highway speed are gone. I didn't mess with the weights, although on one tire I want to every time I look at it.
One wheel has 4 of these lined up on the outside...

 

[maclean216]

I just rotated them for the first time. I'd put about 8K on them. So not often enough, apparently.

On my 4runner and I am the original owner with 203,000 miles.
I have found if you are not rotating tires at 3000-5000 miles and stay aggressive with the rotation..you will see uneven tire wear. Mine wears faster on the outward side on the fronts and even out back. I just waited till 7500 miles on this last rotation and it was way to long. I have major wear on the out side front tires.
One thing I may try this time is having the tires flipped on the wheels to make them last longer. I ~ 25,000 miles on my duratracs and it seems I have about 50% tread left.