Re: Lurching 40 to 50 mph slight hill
 

Just above 40 mph with the torque converter locked, flat or slight hill (2-7 degrees), slight throttle that keeps torque converter locked but puts some load on drivetrain. AC on, but I don't think it makes a difference.

Jerks longtitudinally, like poor gas with engine miss but no engine light comes on.

Local dealer has requested GM to send an engineer to look at it. They have seen it on on several H3's but none as worse as mine.

Re: Lurching 40 to 50 mph slight hill
 

Just did some extreme ascents in CO, and had nothing like this happen. Didn't downshift as fast as I would have liked, but overall, it ran the mountains surprisingly good.

Re: Lurching 40 to 50 mph slight hill
 

Running in the mountains is no problem. I too did a trip in the CO mountains over the fourth and didn't notice it until I can back to town. As noted, it is mainly on flat roads going around 40 to 50 mph with light throttle.

Re: Lurching 40 to 50 mph slight hill
 

I don't remember which thread I said it in, but mine also does this. The shop manager took it for a drive, with me in the truck and duplicated it.

He said he didn't know what it could be, maybe the TC sticking? He said he would have to drive a few others to see if they did the same, then he would get back to me.

I haven't heard from him regarding this, he probably forgot.

Re: Lurching 40 to 50 mph slight hill
 

hey i tried to recreate this but i wasnt able to. I was cruising at around 40 on a flat road and then also tried on a slight hill.

I didnt feel any tipe of lurching or anything. The engine felt smooth and held the rpms constant. I had a passenger with me in case i couldnt feel it but they didnt feel anything at all either.

Re: Lurching 40 to 50 mph slight hill
 

So at least it isn't a universal design fault, I hope, based on your experience. Negates GM's "it is normal".

Just wondering, what temperatures were you all driving in? Here in Las Vegas, I kinda wonder if it started in March when the temperature warmed up, and when I was in Colorado it was cooler and not so noticeable.

Re: Lurching 40 to 50 mph slight hill
 

when i checked if mine had the problem the temp was around 80 degrees, however here the temp goes from as low as -10 in some winters to high 90s and in some cases over a hundred.
never experienced anything like you are describing in any temp.

Re: Lurching 40 to 50 mph slight hill
 

Well, that blows my idea of high temperature causing it because it definitely occurs on mine at 80F.
Just noticed that I can't turn off stability control with the dash push button.
I wonder if the problems are related...

Re: Lurching 40 to 50 mph slight hill
 

Duh, it helps to read the manual. Have to push the button for 5 seconds, and then a light on the left side goes on, not the button itself. Definitely not related. Unfortunately.:(

Re: Lurching 40 to 50 mph slight hill
 

So finally called Hummer Customer Assistance after local dealer, rep and GM engineering have found no solution to lurching with about 10 days total of trouble shooting. They will be talking to the local dealer and then get back to me.

Does anyone know what is the next step to try to either get it fixed or get a buyback under the lemon law?

Re: Lurching 40 to 50 mph slight hill
 

Mine is fixed, Front differential Carrier Bushings.

Re: Lurching 40 to 50 mph slight hill
 

Make sure that you have in writing that they recognized the problem and couldn't find a solution. If you want out of the vehicle, there are law practices setup up for lemon laws.

Re: Lurching 40 to 50 mph slight hill
 

Mine has started doing something similar after I put oversized (35") tires on it. I have only had it do it twice but my fience who drives it daily says it does it pretty often. I just figured it was due to the oversized tires but like I say I have only felt it twice so I havent been able to really get a good idea of what it really is.

Keep us updated.

Re: Lurching 40 to 50 mph slight hill
 

Can you provide the part numbers that were replaced?

And where/what are these bushings?

Re: Lurching 40 to 50 mph slight hill
 

I had a different issue going for 2.5 months. GM/Hummer Corp. strongly encouraged me to go to another dealership AFTER my service dept and Hummer tech (regional tech) checked mine out and said it was 'normal for H3's". I knew it wasn't normal. I also had to resort to GM Corporate Customer Service .. first, the cust. serv. person had to call the dealer to get their thoughts on the problem. When that person told me "it sounds like it's normal for H3's", I asked for the next person in line above her. It was the next customer service person above her who told me that another dealer might have a 'fresh pair of ears' and may have heard of my problem before. He was right. I finally bit the bullet and drove to another dealer who found and fixed the problem in ONE day. It has been 2 weeks and so far, so good. I drove up and down Mt. Charleston this past week in LV and didn't have any problems. I know you have one major Hummer dealer in LV .. are they the only ones available to you? Good luck! Keep us posted! (By the way .. my problem wasn't something normal).

Re: Lurching 40 to 50 mph slight hill
 

Could you please post what was replaced?

Re: Lurching 40 to 50 mph slight hill
 

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!!!!!!!!! :twak:

Re: Lurching 40 to 50 mph slight hill
 

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

Glad it's fixed now

Re: Lurching 40 to 50 mph slight hill
 

Re: Lurching 40 to 50 mph slight hill
 

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.