Drive shaft balancing. Carrier bearing for drive shaft. That's what I'd be looking at for rear vibrations

 

Guys,

Here is something many people do not even know about, and this included people who mount tires for a living. There is ALWAYS a colored dot on the sidewall of the tire that is supposed to be matched up to the valve stem. This aligns the high spot on the tire with the low spot on the wheel, or visa-versa (I can't remember). If you don't do this, you will more than likely wind up with an imbalance condition that will take much more weight than is usually necessary. I have seen these dots in many colors, (white, yellow, green, blue, etc.), but they are ALWAYS there unless they have been rubbed off from the tires being stacked while in storage.

Here is a picture of one of mine on my A/T3 tire. It's yellow and about 3" out from the valve stem.




RON

 

I always keep my tires rotated, run max pressure, and have front end alignments done. I have been using Centramatic tire balancers on my truck, my semi, and my dads '01 superduty. I ran 3 sets of Firestone (265/75R-16) Steeltex A/T's on two different trucks('97 and '99 F250). Got 50-60,000 miles out of each set. I loved those tires, wish I could still get them. I went to get a 4th set and they had discontinued them and came out with the Transforce to replace the Steeltex....piles of crap. What a waste of $750. I was able to squeeze a good 30,000 miles out of them and they were all completely balled--not to mention they made more road noise from day 1 than the steeltex. So on this go around I ordered some of these new fancy Cooper AT3's....I have about 10,000 on them now and am not impressed. My balancers have done an excellent job on everything else, even my dads truck with 9.00-16 military tires. It took me a while to realize that these tires are VERY heavy on one side. I have even had them trued up (I have done this to several sets of tires so far-- best money you will spend on your tires) which helped a lot but they still wont balance, so I'm about to find out just how many oz. of weights it is going to take to straighten these junky things up. At 1st I thought maybe I had just got a bad tire or two and then I found all the post on here about others having the same problems. I dont know about you all, but Buying $700-$800 in tires is not something I like to do on a regular basis. Sure with I could get me another set of Steeltex.

 

Rongold- thats interesting. I have mounted many tires and even seen the marks before...but never gave it a second thought. I will definitely look for this on the next ones I put on.

 

Also ......These tires seem to be very stiff. They do not give to the road at all. Is it actually the rubber being more hard or dense?

 

Interesting thread guys. I put a set of Cooper AT/3's on last September and noticed a vibration at 60-65 mph also with a steering wheel shimmy. After 7000 miles and a trip down South, I had them rebalanced with no real benefit. Before my last camping trip up North, I was airing up the tires and noticed my R|R had two 2" splits or cracks about 3" from the rim running parallel to the rim. I thought I may have sliced it by running over something sharp. There was no visible abrasions nor damage that you'd normally notice when hitting something. I took the truck back to the shop where I bought the Cooper's and bought another replacement. Since then there has been no noticable shimmy nor vibration at any speeds. Maybe a bad tire with bad belts?
MIke

 

sounds like a bad tire to me. I have had several sets and I have them on my car as well with no issues. I get mine at a big rig truck repair shop so then know what they are doing.

 

You mean Tire Farm in Farmingdale? I wouldn't trust anything those guys say, I went there for a set of BFGs they told me they had in stock on the phone - show up and they don't have them but they have this that and the other thing. As I stood there pondering I was watching some guys working on the cars and decided to get out of there and never go back.

 

Guys,

I've been searching the net for Cooper AT3 tire issues and landed here. I have the exact same issue. I purchased a set of these a year ago and have had nothing but problems. Unfortunatly its my mistake as now i have too many miles (20K) to do anything about it. Originally when i bought these tires they had slightyly more vibration than my old Goodyears. Not terrible but i was expecting less vibration so was surprised they were slightly worse than the old goodyears. So when i got home i looked at the tires and noticed all of them had at least 4 oz of weight and 2 of them had 8-10oz. Weights everywhere. One of the tires has 5oz on the outside of rim and 4.5oz on inside of rim. This was way more than the goodyears and they still had a questionable ride. My dealer said that was normall so like a idiot i left it alone. Now with 20k i can't hardly bare it at 65-70mph. The bad thing (should be good) is that the tires look new with hardly any wear. I should be loving life right now but instead i'm very pissed off as these 20" tires were over a grand for the set. I will never own another set of coopers. Especially after reading this thread.

 

guys go to the local walmart or farm and fleet etc, buy some airsoft bbs, and throw them in your tires(approx 6oz per tire for stock sized) then have them aired up and spun, watch in awe as you won't need any balancing weight. Been doing this since 99 when I was running 37" swampers on a JEEP. Always stayed in balance, and no weights to fall off.

Heres a link for amount of bbs to tire size :http://www.innovativebalancing.com/BigTirechart.htm

 

i run alot of coopers, i have 3 sets for the excursion and 2 sets for the explorer. none of them have vibration issues. i plan on getting the AT3s for my expedition next summer.

i have a few different models ATR,STT, ZEON LTZ, M&S studded. all have balanced near perfect and one set is from '07 with no signs of weather checking or cracking. i hope anyone with an issue can get it resolved because in my opinion cooper makes a wonderful tire.

 

Yeah I am really suprised as well. I have CS4's on Buick and I have run them in the tripple digits and they are smooth.

3rd set of the STT's on two different trucks and they have all been good.

That is why earlier I mentioned that I get my truck tires at a truck service center. They know how to deal with the larger stuff.

 

its funny you mention it, the place i buy from and mount/balance deals mostly in big rig tires...might be something there

 

I had a set of cooper discoverer atr's on my previously owned 2006 superduty. Tires got great traction in the snow and wore great! Never had any issues with them. I put around 38,000 miles on them before the truck was traded in.

 

Where did you get yours put on? did you use a truck place or just a tire dealer?