2004 chevy colorado
z71
4x4
ext cab
67k miles

when moving at idle speed/just barely touching the gas, there is a metallic sounding squeak from the rear end. started after my back wheels were off the road and when I hit the gas, the tires spun, then hit the pavement and caught traction, producing a hard jerk and what seemed like the rear end locking up for a few seconds.

8/15/2010 11:47:39 AM

you sure it's not brake squeal that just happened to start right after your shenanigans?

8/15/2010 12:02:40 PM

well, it happens without the brakes on... so... and I didn't mean to do that didn't realize my tires weren't on the pavement

I guess it could be a rock in the rear drum?

8/15/2010 12:42:53 PM

could be time to change your rear diff fluid and add some positrac additive to it maybe? quick fix, easy to do yourself depending on your rear diff cover layout.

does it sound worse when turning at slow speeds?

8/15/2010 9:43:11 PM

"positrac additive" = friction modifier

8/15/2010 10:48:05 PM

GM trucks typically have a gov-lock (if it isn't an open differential), so no modifier is needed.

8/16/2010 8:45:41 AM

sound doesn't change when turning... at least from what I've noticed. it seems to have gone away today... or maybe I just didn't hear it/am getting used to it.

8/16/2010 11:19:49 PM

well it's definitely not gone... getting worse. loud squeak now and when it happens, I can feel the truck slow down (going at idle speed).

9/2/2010 4:45:19 PM

brake pad wear tab!

9/2/2010 5:30:20 PM

u-joint

low brake pad

[Edited on September 2, 2010 at 6:25 PM. Reason : just watched the video]

9/2/2010 6:24:08 PM

have you taken off the rear drums yet?

Sounds like the drums are warped or one of the shoes is stuck/prematurely worn based on the video but I don't know why the grass/pavement incident would cause it unless you just started to pay attention to any sounds more closely. Maybe just enough flex in the axle shaft/hub when the tire(s) caught traction for the drum to swipe and grab one or both of the self-energizing shoes and lock up the rear end momentarily?

9/2/2010 10:00:51 PM

oh yeh, had all 4 brakes checked today... in great condition, barely even dirty, no issues whatsoever

9/2/2010 11:33:16 PM

well that was the relatively cheap stuff. Now you're talking possibly the axle shafts or bearings.

I couldn't tell from the video, but was the truck slightly swaying forward every time that squeak occured?

9/3/2010 11:23:07 PM

not sure what you mean by swaying forward... each time i heard the noise I could feel the truck slow down, like I was braking and the front end would drop slightly (just as in braking).

the frequency of the noise is proportional to speed, but above a certain speed (not sure what yet) I no longer hear it.

sounding more like the axle, rear diff?

and again, this is without applying the brakes... so unless they're engaging improperly, I'm guessing this has nothing to do with them.

I do have horrible front brake squeaking though... I mean horrible, but the brakes are in good condition... wish I could do away with those squeaking as well

[Edited on September 4, 2010 at 2:21 AM. Reason : .]

9/4/2010 2:18:11 AM

All the duralast and wearever brands I've had horrible squealing and cracking but I know they are cheap for a reason. By swaying forward yeah I meant it looked like you were tapping the brakes every time it squeaked. It actually reminded me of that exact symptom/issue a couple times when my front rotors were badly warped (which at one point occurred on all of my cars, especially the Ram) but didn't squeak. I'm fresh out of ideas but I know someone else has to have some alternative ideas. I'd grab a buddy to sit in the bed and try to pin point if it was coming from the wheel/hub areas or the diff.

9/6/2010 1:02:24 AM

^yeh, I should have done that this past weekend. and I wished it was something simple like rotors anyways, I'll try to throw a roomie back there today and test his hearing. as for the front brakes, I'm not sure what's on there... I'm too lazy to change my own brakes... but I may next time just so I can get a good, personal look at what's going on.

9/6/2010 8:34:32 AM

What about the e-brake shoes? Don't you have smaller shoes in the rotor hub for e-brake use? Did anybody check them?

9/7/2010 12:09:07 PM

I would be pulling the diff cover and inspecting teeth/looking for metal in the fluid.

9/7/2010 12:12:56 PM