Jumping on the Cooper AT3 bandwagon......

[little_joe]

...and likely jumping right back off.

Cooper AT3 275/70R17 Load Range C on an '07 GX470 97k mi using '14 T4R Trail wheels. Drove into the tire shop with 255/75R17 Hankook Dynapro ATM, ~18k mi on them, everything was smooth as could be, ride was perfect.

First set of Coopers were way out; did a road force balance, still shaking and shimmying like crazy. The first night, they seemed to have flat-spotted overnight - ride was akin to wooden blocks until I did over a mile at 45mph; then they were merely awful. Straight back to the tire store........

Second set of Coopers were way out; did a road force balance with 3oz, 6.5oz, 5.5oz and 5.5oz and they're sort of close to being balanced.

Having used Hankook MT, Bridgestone Dueler MT (way back in the day), BFG AT, Dynapro ATm, Grabber MT's, original Goodyear MTR's, and Buckshot Mudders in the past on other vehicles, these are closest to the Buckshots in onroad ride quality, possibly approaching a Swamper.

Is it just me? (I suspect it is)

 

[tgreening]

I had a set on my van, 235/85R16, load range E and they were smooth as silk, with about 4500 miles on them.

 

[jeep-N-montero]

I don't think any of mine took more than 1.5 ounces and the truck rides smooth even when towing our big boat.

 

[1stDeuce]

Sounds like your tire shop may have a balancer problem... That is WAY More weight than you should need. You might try someplace else before canning the tires. Your experience is NOT normal for Coopers, or AT3's.

 

[texascrane]

I've got 28k on mine in 270/70r18 (Load E) with no issues.

 

[87Warrior]

I am sorry you are having such a bad time with the AT3

The AT3s really are a great tire, along with Cooper in general. I am on my 4th set of Coopers and haven't had any issues. Cooper does have a good warranty, hopefully it will continue work in your favor.

 

[kojackJKU]

Def. a balancer issue.

 

[Eaglefreek]

My understanding from speaking to a someone who calibrates them, not many installers are trained properly to use the Road Force and they need to be calibrated on a regular basis, which doesn't happen as often as it should.

 

[kayadog]

I don't love my AT3's and won't buy another set. The traction and wear is good but they became very loud after 20k miles, especially for a tire with a mild tread pattern.

 

[little_joe]

Hrm, maybe I will try a different shop for balancing and see if that produces any better result - honestly hadn't thought of that. I can't believe I'd have 8 of them that are so far out as to be undriveable. They are very quiet and at the occasional speed I don't get shake/shimmy, ride quite well, so it may be worth chasing this a bit longer. Thanks for the suggestion!

 

[kojackJKU]

I know when I get my tires installed at my local mechanic, his balancer is WAY off. Its horrible. So I just goto the local tire shop where I buy all my tires to get anything balanced and installed now.

 

[little_joe]

Well, the Hunter GSP7000 was able to get these tires balanced, and they ride acceptably. However, 2 of them were so far out of spec on runout, the 2nd shop said they'd have sent them back to Cooper; and I'll be relegated to rotating side-to-side only. I'll be calling the original retailer Monday to see about replacing them. O well.

 

[kojackJKU]

Time to try a different tire! I agree if they are that bad.

 

[kayadog]

I had the same issue with a set of General Grabber AT2's. I ran a set for 70k trouble free miles, then all four of the replacement set I bought were badly out of round and horrible.

 

[Applejack]

My brother has a set on his Honda Pilot and I was really surprised how noisy they were. I would have sworn they were a mud tire. Not at all what I expected. The ST Maxx I had were much quieter.