Suspension rattle

[spasm3]

My avalanche has this annoying rattle. Now i know its 17 years old, but i'm trying to sort it out. Its not exhaust. It never rattles with weight in the bed, and it never does when i have my travel trailer hooked up ( weight distributing hitch). The front and rear sway bar end links and mount bushings have been replaced. Its toward the rear.

This truck has independent rear suspension. I have replaced the left to right track bar.

I'm currently replacing the parking brake shoes and the rear brake dust shields that have rusted away. I can't reproduce the rattle by shaking the upper and lower control arms. Its not the spare tire.

But should i just replace them? There is an upper and lower rear arm on each side.

What would cause and unloaded rattle?
Some pics.

 

[irad]

With the tires on the ground go around the underside with a rubber mallet. Hit different areas and listen for the vibration.

 

[Kestas]

I had a bad rattle that was traced to the spare tire. Once the suspension checks out okay look for rattles in the body, which are often louder than suspension rattles.

 

[Danno]

Side topic, what would cause that kind of corrosion in North Carolina. Used to see that in our winter salted roads in the great white north, but in North Carolina? Sea salt air?

 

[The_Nuke]

Can you record a snippet of it rattling to post up?

I had an annoying rattle once on a ‘96 Tahoe which sounded like a chain was dragging behind me when I hit bumps. That turned out to be the shackles on the leaf springs. A little electrical tape fix that right up!

 

[spasm3]

Originally Posted by Danno
Side topic, what would cause that kind of corrosion in North Carolina. Used to see that in our winter salted roads in the great white north, but in North Carolina? Sea salt air?


Previous owner had put boats in salt water. Truck had been on the beach. Did not have much rust when I bought it. But it progressed since I owned it.
I bought it in 06 with 25k miles.

It's odd how some things are very rusty, yet others in the same proximity are not.

 

[spasm3]

I may have found the rattle. Might not be suspension. While changing the e brake shoes I was beating around the suspension as suggested above.

And this caught my eye. Kind of obvious I guess, but I was looking at suspension. Tunnel vision.

I'm guessing it did not rattle with the camper in tow due to the air flow being different while towing. Replaced both sides with some clips I have, if they hold.

 

[spasm3]

Happy to say that between replacing the rusted out parking brakes , and the above body molding reattachment, the rattle is gone!!