I have an 06 H3 that I just replaced the radiator in. I went to the parts store and bought some 1/4 inch rubber tubing, Split it with a razer and put it across the radiator support where it was close or was making contact with the radiator. I'm hoping this prevents the cracking issues.

 

A better solution is to grind off the protruding lip of the support with a flapper wheel and touch up the cut edge.
You want no contact at that spot. Even with the rubber hose you added, the support is still putting pressure on the plastic tank.

 

I as well just joined the unfortunate cracked radiator group. But I was curious to if an extended warranty would cover this?

 

All depends on what is included in the warranty plan???

You could read the entire contract, or do like I(service manager) do, just call the 1-800# and speak to a rep... I tell them what part failed & how much I need to fix it.. They will then tell me if it is covered, and if they agree to my charges(sometimes I have to adjust a few bucks lower to get the job).
I've done alot of extended warranty service over the years, most reps I've dealt with are easy going, some tough. Bottom line, those reps get paid to deny claims.... Just find out, if it is covered under the warranty plan, that you have. GL

 

My dealer (Al Serra Colorado Springs) where I bought my 2008 new does the oil changes and they noted mine was cracked but not leaking. They stated they only change the radiator if it is in fact leaking.

Any advice?

No mods and I never went offroad. 40K miles. I love this thing and I'm looking to drive it until it is no longer road worthy.

Has GM acknowledged the design issue?

 

To anybody that has their radiator crack on their hummer h3. Call the hummer customer service at 866-486-6376. let themknow you are calling because your radiator has cracked. Be sure to let them know that several hundred other h3 owners have ad the same problem. Mine cracked. I have 61,000 miles on mine. I called them and they had me bring it to a local dealership to have it looked at. The hummer rep them turned it over to GM. The GM rep called meand I explained that my radiator had cracked just like the several hunderd other h3 owners I read about. Thru several calls first thedealership said they would cove hale of the replacement cost. I then called the GM rep back and informed her that I had spoken to hundreds of owners that had theirs replaced at all different mileages and that I was going to contact all the owners that I could and file a class action lawsuit if GM didn't replace my radiator for me. Giving that it has happened to alot of people, it was a design flaw in the making of the radiator. After several calls GM decided they would replace my radiator for me but I had to pay just a $100 deductable. No I don't have an extended warranty. My warranty is up. If yours cracks do as I did and call them and insist that they replace it or you will become part of a class action lawsuit to force thm to replace it. Don't take no for an answer. It is a design flaw and their fault, not ours.

 

call hummer customer service. make them replace it. don't take no for an answer. Make them know you will get with other hummer owners and file a lawsuit. They replaced mine at 61,000

 

Cracked=LEAK, it may not leak without pressure.... but if you pressure test it, it will leak!

 

Its still a bum deal. It is just replacing the radiator but doesnt fix the problem. Is there a solution?

 

The problem has been remedied. The new rads have an indent along the top now to prevent this from happening again.

If your dealer is replacing it with the same old style rad you're being ripped off.

Ask me how I know..