Clunk in transmission

[MaLLHPPR]

I've had my H2 about(14 days, 1 hour and 50 min - but who's counting)

I have noticed, just driving in town, when I push the brake but don't stop all the way- then immediately after, step on the gas, there is a "clunk" right after I step on the gas. I'm not slamming on the brakes then pushing the gas pedal to the floor. This is just under normal driving. Sometimes it is more noticable than others. The transmission shifts smooth any other time.

I just wondered if anyone had some idea of what this is?

[MaLLHPPR]

I've had my H2 about(14 days, 1 hour and 50 min - but who's counting)

I have noticed, just driving in town, when I push the brake but don't stop all the way- then immediately after, step on the gas, there is a "clunk" right after I step on the gas. I'm not slamming on the brakes then pushing the gas pedal to the floor. This is just under normal driving. Sometimes it is more noticable than others. The transmission shifts smooth any other time.

I just wondered if anyone had some idea of what this is?

[NSXTC]

Where is the clunk coming from? Front? back?

Regards,
David
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H2SUT.com
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[MaLLHPPR]

It feels like it's coming from the front.

[Mango]

Got the same thing. Only happens when I stop firmly and take off quickly, I think. Not sure if it is the suspension or the drivetrain but think it's the drivetrain, maybe even the transfer case????

Mango -- Saltwater Flyfisherman, Photographer, Varmint Hunter -- Fort Worth, Tx

"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."

[NSXTC]

Yep. Verified mine does the same thing.

[MAC]

I tried it out several times tonight exactly as you described, but I did not hear any "clunk."

[NSXTC]

Don't use the brakes. Just let off the gas and hit the gas again. The test works best for me < 20 MPH.

[alpha]

It's "play" in the driveline. Small tollerances stack up by the time power hits the tires. I've owned a LOT of trucks and it's very common in 4WDs. My Landrover Discovery was REALLY bad. I did some battle with the Rover dealer over what I thought was too much. I call it "backloading", the technical word is "backlash". The driveline wants to push against the slowing wheels, then pulls against them to move them foreward. Play in all the gears creates a thunk if pressed too hard too quick. I found that it needs to be managed well, reload the driveline before applying heavier power to it. I can go down the road in my H2 and press and release the accelerator in a rythim and really get it clunking hard (I tested to see what the backlash was when I got it) but it's not bad at all compared to some trucks I've had.

[MaLLHPPR]

Thanks everyone for the input. I've had several 4WD vehicles (mostly suburbans) but never experienced this. I guess if it doesn't get worse I don't need to worry.

Thanks again!

Kim-

Lovin every minute of my H2!
Sunset Orange, Lux pkge, air suspension, sunroof.

[MAC]

I just dropped off my 5'10" 14 years old off at his friend's house for sleepover, on the way back I tried several times to reproduce this "clunk" you talked about without success, with or without brake, on level ground or on hill. There is No clunk.

[CJ]

I have the "clunk". It is a physical clunk. I cannot hear it although I can feel it. It happens just after a complete stop and at the beginning of the acceleration. I asked the dealer to look at it and as you may of guessed already he could not duplicate it. I plan on stopping by and taking the service manager for a ride.

[MAC]

I can certainly understand the technical aspect or cause of the clunk or jerking motion, but I always thought it is a driver's goal or skill to ensure a smooth transition to prevent such jerking motion. I have been in cars with drivers who drive without such basic skill, always gave me a headache or near whiplash, a big NO NO for a limo driver. At the same time, it is improbable that I would be such a better driver than the other Hummer owners here, as everyone else is reporting the “clunk” except I. Well, I'll try to jerk around a little bit tomorrow.

[rpv]

Mine does not have the clunk, but if it did, I'd be at my dealer to drive it with their tech to show them and get it fixed or else...50,000+++ with warranty, better take advantage, for your H2's sake...let us know what happens if any one of you goes to the dealer and show them the problem. Thanks.

RPV

[rpv]

thanks...

RPV

[kacyk]

I know this thread is old but do any of you still have your Hummers and has the clunk sound gotten worse? I too had a Landrover Disco that did the same thing but my warranty is out in 2K miles. I'd like to address it if the long term results are unfavorable.

[dochummer]

Same question here. I have an 03 that I just brought into the dealer and he says that it's normal for chevy's or gm's to have clunks like that. It's just the slack in the transmission, or when the vehicle is downshifting, and it's in-between gears or something. Said not to worry about it. If anybody thinks it's a real problem, let us know.