Lurching 40 to 50 mph slight hill

[Hmmm2]

Originally Posted by ChevyHighPerformance

Could you please post what was replaced?

Sorry, I thought you were all probably sick of seeing my problem posted here for 2 and a half months. My H3 had that grind in the rear right wheel area when I'd come to a stop. We live on a hill, so going downhill, heating up the rotors .. the grind would get very noticeable as you'd get to a red light or stop sign. Two and a half months ... all I heard was that it was 'normal for H3's". Yet, no one else I knew with H3's had that problem. After encouragement from members here and the GM/Hummer customer service manager ... I went to another dealer who was at a considerable distance from where we live. The second dealer turned the rotors, replaced front and rear brakes .. put new pads. The service manager told me I had a warped rotor. He found the problem in ONE day and took care of it. Soooo, it wasn't normal for H3's!!!!!!!!!

[Wisha Haddan H3]

The 1st dealership couldn't find a simple warped rotor?

Glad it's fixed now

[Hmmm2]

Originally Posted by Wisha Haddan H3

The 1st dealership couldn't find a simple warped rotor?

Glad it's fixed now

Go figure. Very discouraging.

[Boar-Ral]

I have a similar problem with my 2005 H2.* Around 40 mph, if I am trying to maintain my speed or very gradually accelerate, the engine surges, you can feel it, and you can see the RPM rise and fall slightly.* If I try accelerating a bit harder, the RPMs increase and the surging disappears.* I went to the dealership and they recommended fuel conditioner, a new air filter, and throttle body service, because it appeared dirty.* They threw fuel conditioner in, I put in a new air filter, but didn't have time to get the throttle body serviced, though I did buy cleaner so I will be trying that soon.* The problem still exists, so I hope that it is the throttle body.* If not, I'm out a couple hundred for their "diagnostic."* I just thought I'd mention it, since those are relatively easy fixes.* Not the same vehicle, of course, but the limited similarities might be enough that the same solution might work for both.

[Dave LV]

Unfortunately, not the same problem. Mine bucks like poor gas or cylinder misfire, but neither are occurring, and the engine rpm is rock solid. Got a call yesterday that an engineer thinks it is caused by the exhaust system... but I think the front differential carrier bushings sounds more like what is happening. Time will tell as the dealer will look at it more next week.

And again to all, the local Hummer dealer is trying everything and is being responsive - it is a GM design problem that appears endemic to all H3s, more in some than others.

[Hmmm2]

Originally Posted by Dave LV

And again to all, the local Hummer dealer is trying everything and is being responsive - it is a GM design problem that appears endemic to all H3s, more in some than others.

I'm sure your dealer's service dept. is doing all that they can. After all, it's in their best interest to keep you as a returning, satisfied customer. The guys (and gals) at my dealer's service dept. are also good people. The service mgrs appeared almost as frustrated as I was over my H3 issues. But what the GM/Hummer Corp Customer Service person had told me was true ... another dealer's service dept MAY have come across a similar problem to mine and know what to do. I think that my H3 may have been the first one in with the problem and they (first dealer) didn't know what to think of it after trying different fixes. The 2nd dealer obviously had another H3 with a similar problem like mine, so it was a quick fix for them. If your dealer can't locate your problem, then going to another for THIS concern may be your answer. Good luck and keep us posted.

[Dave LV]

Dealer has put on Toyo AT Load D tires and I would say about 70% of the shuddering is gone. Can someone explain why new tires would do this?

Kinda ties in with the problem first being noticeable at around 7000 miles, and getting worse with more miles.