Hello there, I have just recently bought a 2006 GMC Sierra Z71 half ton pickup with a total of 82,000 miles.

Tonight, I was just messing around with my buddies and started shaking the box just to see how tight things were (and messing around), only to hear an odd noise. The noise sounded like almost the wheels weren't torqued down all the way and they were rocking back and forth on the rear drums. I noticed when I got home that both rear passenger and rear driver side wheels had this noise.

What do you guys think the problem is?

Thanks for your replies and help, they are VERY VERY important to me.....you guys have no idea how irritated I am, I've only had this truck for ONE DAY!

 

Try checking the lugnuts if that's what it sounds like. Can you be more specific about the noise though, is it a pop or a loud clunk? It could be simple as backing the rear brakes off a bit to keep them from hanging or even a bad u joint.

 

If they were shaking the bed from left to right it is the clearance in the axles shafts to the differential center pin. The pin that keeps the C clips from coming out of the axles. All normal. Any semi-floating rear differential chevy will do this. And if you do front to rear you will get some lash between all the drivetrain components (clunk). Normal

 

Acnas,

Your reply is very relieving. Today I crawled underneath the truck while a buddy of mine rocked the truck back and forth and the sound sounded like it was coming from in side the rear end, either in the axle areas or the pumpkin. I couldn't quite pinpoint where the noise was coming from. Today, my same friend that rocked my truck has an '04 GMC Sierra and I tried rocking his and I didn't notice anything like the sound mine was making. His truck does have 285's on it and was much harder to rock back and forth but I guess why didn't his do this?

 

MrDragon,

Thanks for the reply!!

The noise is definitely a a popping noise like (so hard to explain!!!) something is moving back and forth inside my rear end...any ideas? Thanks!

 

What Acnas said... He couldn't have described it any better. But you may want to check your fluid level in your diff.
I've never heard of it being described as a POPPING noise. More of a clunking noise.

 

If i posted a video on youtube of the noise I'm experiencing, would you guys be able to watch it to get a better idea?

 

Might help?

 

Wow, late reply. I really hope this isn't abandoned lol. I have a video though of it. its in the link below.

Before that though, I just want to tell you guys I really appreciate all of your help and words. Thanks a ton.

-Zach
Heres the link:

 

I still say normal.