massive clunk/knock noise

[Mr Hank]

I had the identical problem at 55K on my H3. Seems that H3's have a way of busting their motor mounts. Mine was the right motor mount. It's pretty common for this to happen the guys at hummer explained to me

[richl]

its not in the motor nor the tranny mounts. the engineers have the entire torsion , front end out on the ground scratching there heads.........

its a actual shifting of the suspension ........

[richl]

update............................................ ............
after 2 weeks in the shop with a "engineer" looking at it . they tore the whole front suspension . with no problems found. even though the engineer felt it ...... told the dealer ship to put it back together and thats all they could do ......

now i am pissed............ going to the lawyer tomorrow and filing a lemon law suit.. and gm wonders why there going broke.........

[nicos]

have seen some info somewere,cant remember where about a bracket that holds the steering rack to the chassis coming loose.
apparently even if you tighten it still loosens after a while and makes a clunking noise up front.
may be thats were your problem is!

[HummBebe]

Carrier Bracket bushings and steering brackets. Here is one link....
http://www.elcovaforums.com/forums/s...arrier+bushing

[pdsq99f4]

Originally Posted by Mr Hank

I had the identical problem at 55K on my H3. Seems that H3's have a way of busting their motor mounts. Mine was the right motor mount. It's pretty common for this to happen the guys at hummer explained to me

I think you're talking about body mounts. They just make a noise, not break.

[Killer]

I had this same noise / issue and confirmed that it was the front diff bracket. I obtained the part number from my local Hummer dealer (50 miles away) and ordered the part from my local Chevy dealer ($75.00). Once it came in (2-days) had it changed by a friend of mine who owns an automitive shop. The entire fix cost me $291.00 and guess what? No more noise!! My H3 is back up to 100%.

ps - My front diff had no issues and no damage which was a good thing because my H3 has 74K miles and is still going strong.

[3Hummer]

sorry for bringing up an old thread but finally just saw it now after a new one on the topic was created...im pasting what i wrote in the other topic on here for ease so please if anyone can help let me know


Ive had two H3's now one 2007 H3 and now a 2010 H3 Alpha....both have done it for their entire lifespan so far. Ive taken it (both) to the dealership to try to imitate the sound because they said they cant fix it unless they hear it to know what it is before they attempt and since it didnt repeat at the dealer they cant do it. One thing i did notice though is a jump in RPM it seems as if the RPM's stay low and then once that clunking sound is done they jump up then switch gears. The problem is exactly as described in this thread and sounds the same. So any idea what it could it besides whats listed in the other forum? or could the RPM jump just be a result of the engine mount being loose and the engine shifting?

[wpage]

Under what condition is this happening?

Is it in 4wd high?

Is it in a turning situation while braking?

What conditions have seen success in what solutions.?