Bad Rattling sound

dh0765 · March 1, 2016

My truck is a 2003 Silverado Z71 4x4, and has 70k miles on it. Alway's garage kept, etc. I have developed a problem with a really fast/loud rattling sound, and it only when traveling over really rough pavement or driveway. I think it has to be suspension related, but can't determine what it would be. The first time I heard it, I thought it was some type of gear stripping/grinding, but I now think it is rattling and has something to do with the suspension system. I know I am not being real clear on what it sounds like, but it is hard to describe. Like I said, it is a fast rattling sound, almost to the point it could sound like gears slipping/striping. Upon looking, the only thing I can find wrong is on the drivers rear side, the bump stop is missing. I can't imagine that is causing the sound I am hearing, as that should only have an impact if hauling something really heavy or doing something to bottom out the suspension. I am replacing it, but the other issue seems to be more critical right now. The only time I hear it is on really rough road or on a driveway with large rock that causes a lot of suspension jumping. Any ideas what this could be?

Edited March 1, 2016 by dh0765

nickc12 · March 1, 2016

My truck does the same thing, I'm a GM ASEP student and have been in a dealership for almost two years and from what I've seen its usually the intermediate shaft. Really not dangerous, but if the sound bothers you they run about 75$ online.

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dh0765 · March 2, 2016

Thanks for your reply nickc12! Its not the intermediate shaft sound, as I am aware of that clunk, and replaced mine some time back. This is a MUCH LOUDER rattling sound from under the truck. I can't stress how loud and serious it sounds. Sounds like it is from up under the rear of the truck. I think it is a rattling, but could almost sound like a gear grinding/sound. I really don't think it is gears though, and more like something with the suspension.

silveradosid · March 2, 2016

ccheck your sway bar bushings

Gurrzt · March 2, 2016

Let your ho out the tool box brotha (word)

dh0765 · March 2, 2016

Bump.... Anyone have any other suggestions of what this could be? I wan't to clarify that this is not a clunk sound. It is a loud rattling sound and only happens when I am on a really rough surface that shakes the suspension quickly.

cjb321 · March 3, 2016

check the sway bar bushings like silveradosid said, i had an old regal that rattled and thats what it was.

dh0765 · March 3, 2016

I did check and they appear to be fine. Bushings look fine, and no movement.

Edited March 4, 2016 by dh0765

dh0765 · March 4, 2016

Any other suggestions of what I can look at?

Don'tGiveATruck · March 5, 2016

My front brake calipers didn't have the little clips that the tops and bottoms of the brake pads ride along and that caused a bit of a rattle. It wouldn't rattle when I had my foot on the brake but when they were loose they made a bit of sound on rough roads.

Nanotech Environmental · March 5, 2016

Any other suggestions of what I can look at?

It could be a couple things-

-The mounts for the lower rear shocks are not fully tight. If this is the case, they make a lot of noise from jostling over every single bump in the road, large and small. They need to be pretty tight, and the lower shock eye can come loose in the shackle mount over time and use. I had this happen recently, and was a bit flustered about what it was for a while. Once I found the cause, it took a couple minutes with a couple wrenches to tighten things back up. If you can wiggle the shock by hand, its too loose.

-Something is wrong with the rear springs, or spring mounts.

-You could have something going wrong in the rear axle/differential, which could be pretty serious.

Edited March 5, 2016 by 3beejay3

Silverado4x4 · March 5, 2016

Do you have step bars? Sometimes they can do what you describe.

BlackZ71Silverado · March 6, 2016

If it's possible for you to post a video of this sound, you may get a few more responses. It is really difficult to diagnose a sound over the internet without actually hearing what's going on.

ifixedit · March 8, 2016

I know exactly what's making that noise. The 03's (and other years?) have that annoying steering column / steering shaft rattle / clunk that will develop / worsen over time. Yes, it does it over bumps, even on some fairly minor bumps, mine does it as well. It is supposedly due to lack of grease where the steering shaft pieces slip over each other somewhere under the hood. Mine has been more minor so I haven't investigated yet, but a friend had the same problem with his 03. Sorry I don't have all the details but I guess there's a bolt you can take out and slide things back and forth to get the grease where it's supposed to be and you can also then re-grease, put it back together and the noise will go away, although this is reportedly the more temporary fix. I understand there is /are replacement part(s) that fixes the problem permanently.

Edited March 8, 2016 by ifixedit

dh0765 · March 9, 2016

Olwhiskey - I checked the clips on the calipers all the way around and they are all fine, and everything is good and tight. No problems found on that.

Silverado 4x4 - I do have bars. I checked all fasteners and they are all good and tight. No problems found on that.

BlackZ71Silverado - I will have to do this and see if I can get something posted.

ifixedit - You are referring to the intermediate steering shaft clunk issue. It is not this. It is not a clunking sound, it is a loud rattle. I fixed the intermediate shaft issue years ago with the new part that fixed that issue.

Edited March 9, 2016 by dh0765