Clunk Under Floor During Hard Turns?

[Sundown94]

Matt, that sounds extremely logical and -- so far -- the most likely cause of the clunk. It's funny that you say body mounts because one of the possibilities that I came up with last night while I was driving was body mounts (maybe the whole cab was moving on the frame), but then I thought "how could that be?". It would also make sense that I felt it for the first time last night because it has been raining hard up here in the Northeast for the whole week and last night was the first time I drove the H2 since Monday (when it was dry out), so the body mounts might have been wet and more prone to "slip". I will see if it stops today or tomorrow now that we have dry weather here. If it does stop "clunking", then I think this comes close to proving that it is the body mounts.

Thanks again, and if anybody else disagrees and/or has any other ideas, I would certainly still welcome them.
Sun-

[mikejr]

Originally Posted by Sundown94

Matt, that sounds extremely logical and -- so far -- the most likely cause of the clunk. It's funny that you say body mounts because one of the possibilities that I came up with last night while I was driving was body mounts (maybe the whole cab was moving on the frame), but then I thought "how could that be?". It would also make sense that I felt it for the first time last night because it has been raining hard up here in the Northeast for the whole week and last night was the first time I drove the H2 since Monday (when it was dry out), so the body mounts might have been wet and more prone to "slip". I will see if it stops today or tomorrow now that we have dry weather here. If it does stop "clunking", then I think this comes close to proving that it is the body mounts.

Thanks again, and if anybody else disagrees and/or has any other ideas, I would certainly still welcome them.
Sun-

I had the same issue in my 2006....dealer couldnt find the source since it was so intermittent. So i fixed it myself and bought a 2008...lets hope i doesnt happen with the new one. I recall someone posting on here that if you torque the body mount bolts a bit it will stop the clunk/creak.

[Vettster]

Had the same thing happen on my 06.
Dealer replaced the right rear body mount and all is well.

[tower]

Do you bowl?

[3Hummer]

sounds like you guys need an H3

[RippSpeed]

I have kinda same problem except only happens during stop and go traffic or coming to a stop... Where the my rig is rolling at 10 to 15mph ( rolling to a stop ) and then traffic starts to move and give it just enough gas just to get it moving again... I hear a loud clunk under my rig... Sounds like a axle or a motor mount or even a transmission mount gone bad...

[3Hummer]

might be the transmission downshifting

[Aich Tew]

Originally Posted by 3Hummer

sounds like you guys need an H3

I'd buy an H1 if it would fit in the garage.

[Sundown94]

RippSpeed, the clunk you are talking about is another totally different clunk that also happens to me at the same time (rolling 10-15MPH and hitting the gas). I believe 3Hummer is correct in that this problem is related to the transmission downshifting. I personally can't stand it, but have no idea how to fix it.

And just to provide an update to the original issue that prompted me to start this thread, the clunk that I felt through the floor seems to have gone away after the weather dried up. I am waiting for more rainy/humid weather to see if it comes back, at which point I think I would be able to conclude that the clunk is in-fact caused by the body mounts and is directly correlated with rainy weather (and therefore nothing to worry about).

Thanks for all of the responses guys!!

[porschett]

Originally Posted by 3Hummer

sounds like you guys need an H3

Funny you should say that, I just pulled out a H3 that flooded in 2' of water.