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The infamous "clunk"

kjzeusman

Full Member
Joined
Sep 1, 2007
Messages
35
Location
Canada
So I've been reading through all the threads about the famous "clunking" noise folks are reporting hearing on their Av's.   The theme for fixing seems to be consistent:

1.   Crossmember
2.   Body Mount
3.   Intermediate Shaft

I have an '04 Avalanche making the same "clunking" noise, however I do not have the luxury of warranty service.   I don't feel the clunk in my steering at all (nor am I having any issues with steering) and I just replaced all 4 shocks with KYB's.   So my question is, is there any way to narrow down which of these 3 things is causing the issue (lord knows I've tried. . . )?
???
 
body mount..

cross member was first fix... but then GM decided it was body mounts
 
Cool - thanks.

So one more piece of information:  the clunk happens primarily when there is weight in the vehicle i. e. when I have my wife and 3 kids in the truck, the clunk happens when I go over the bigger bumps in the road.   If it's just me in the truck, it doesn't happen much at all (unless I REALLY go hard over a rough piece of road). . .

Given this information, would you still say it's a body mount issue?
 
the body mount issue is where it flexes and makes a funky noise....

So yes the more weight the more likely...

 
Ok, final question before I head over to the dealership:

I've searched the forum again on "body mount(s)" and found lots of information but was unable to locate anything about what these things actually are, how many there are (google tells me that the number of body mounts you have depends on the type of vehicle you drive), or what it will cost me to get some (or all) of them replaced - any thoughts?  I'd like to have at least some idea of what I'm talking about before I start shelling out cash to the mechanic. . . . .

Thanks again for your help - very much appreciated!
 
kjzeusman said:
Ok, final question before I head over to the dealership:

I've searched the forum again on "body mount(s)" and found lots of information but was unable to locate anything about what these things actually are, how many there are (google tells me that the number of body mounts you have depends on the type of vehicle you drive), or what it will cost me to get some (or all) of them replaced - any thoughts? I'd like to have at least some idea of what I'm talking about before I start shelling out cash to the mechanic. . . . .

Thanks again for your help - very much appreciated!

Body mounts are essentially a big rubber biscuit that sandwiches between the frame and the body and has a bolt running through the center to actually attach body to frame.
 
DougD said:
Body mounts are essentially a big rubber biscuit that sandwiches between the frame and the body and has a bolt running through the center to actually attach body to frame.
correct and the issue is they are too short so body flexes when going over bumps... and makes a noise....
 
Any idea how many body mounts are on a 2004 Avalanche?  I've heard 12 (6 front, 6 back) but can't seem to confirm. . .

Any idea what it costs to replace these?
 
Though I have not had to deal with the clunking issue and if it is actually an issue with the height/size of body mounts and body flexing then I would suggest......................1st having someone double check just how tight the body mount bolts were. Maybe theres a few loose ones. Any shop with a lift or creeper could complete that task in 10 minutes with a rachet and a socket. Cost ? Couldn't be much.
If that didn't do it I'd consider installing a body lift. ( $ 300-500_ labor)
I have completed that task recently with a 3" lift for other reasoning. The kit includes all new taller body mounts and bolts in addition to the other necessary parts to complete the lift. ($200-300) Kit cost.
I suppose If I were going to go through the nearly identical labor process simply replacing the mounts in order trying to eliminate clunking I'd opt to raise my AV 1st and kill two birds with one stone. Then you could run larger tires, ie too. That is of course if you were considering doing that as well sometime. It also seems redundant replacing the factory mounts with mounts of the same identical size and ending up with the clunking once again if there being too short is the problem to begin with.
If I weren't wanting to raise the AV any appreciable amount. I would follow the nearly identical process of lifting the body off the frame and simply add a few washers to the factory mounts. Making them slightly taller..Good Luck with the Clunk.....Dave 03whitediamond
 
That's the whole problem - I don't know if it's the body mounts that's causing the problem.   I don't have any plans to lift my Av at this time.   I've already had a friend who's a crude mechanic check out the suspension and he didn't see anything obvious.   Now he wasn't sure about whether or not the body mounts needed replacing or not, but I agree with you in that I don't want to drive up to the dealer and have them replace the body mounts when I'm not 100% sure that's the problem (remember, I'm not under warranty so any work I have done is out of my pocket) :(.   What's worse is the dealers where I live are charging $100/hr. labor rates so again I'm somewhat hesitant to just take it in and have them try and diagnose - that's pretty much a repair shop's dream ("I have this clunking noise but don't know what it is - can you fix it??"  Mechanics from all over the world will be parachuting into the dealership to take my money. . . . ).   At the end of the day that might be my only option because ultimately we're just guessing at the problem here.

Thanks for all the feedback and help - this forum is a very valueable source of information and I appreciate everyone's input.
 
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