Intermittent Rear Noise

[taylorjheinzen]

Hey guys, new to the forum here. Bought an 05 Tahoe LT few months back and it's been nothing but awesome for me. Getting a pretty uncommon noise from the rear the past few weeks and it seems to be getting worse. To diagnose the noise, it's more rattling than clunky. The weird thing is, it's tough to really diagnose WHEN it happens. At first, it happens usually <25mph over a rougher road. I changed the pads and rotors back in spring and when the noise first started happening 2 months ago, the first thing that occurred to me that I didn't torque either the caliper or bracket bolts, so I went ahead and did that. They were super loose, and that solved the problem. For a while. Few weeks ago the noise returned and the noise happens most often when I'm at highway speeds, and not at all <25mph over rough roads. Bumps can make the noise happen, but there's times going straight down a road going 60mph+, and the noise will just be constant. Sounds like something is about to fall off almost.

Here's what I've ruled out.

-Not sure it's the brakes anymore, as I'll lay on them to make sure everything is tight and noise is still there.
-Nothing suspension related, as poor road/terrain has it's moments of silent driving.
-Parking brake. Engaged it while driving (not the smartest thing, I know) and noise was still there.

Here's what I'm suspicious of:

-Rear brake dust shields. They're super rusty but aren't loose or flimsy.
-Spare tire. She's pretty rusted on their and I gave it a few good kicks and she really doesn't move at all, but maybe wind moves it more.
-Rear diff. Almost sounds like some is rattling around in there, but the fact the sound is so intermittent at times makes me rule this one out.
-It could very well just be the brakes and something is still loose when driving. Clips and caliper hardware all replaced with brake job in spring.

Any insight you guys have would be super helpful! Thanks!

 

[Doubeleive]

hmm, I would check the rear suspension over real good, on my 4wd Yukon the rear end had a lateral rear track bar that started making racket and when I replaced it the noise went away they can get worn out and run about $60 online but if yours has one and it is suspect just try tightening it down real good first, I had put a lot of miles on mine and the wheel bearings can make some noise to but that's usually pretty consistent, another thing to check is universal joints and pinion bearing, if its not the gas tank straps, shocks or brake related and still cant find it maybe pull the rear diff cover and see what it looks like in there the rear ends just don't hold up real well after replacing mine 3 times I put in a Eaton Detroit and it never failed again.
also I had a intermittent noise one time couldn't figure it out no one could until one day I ad my foot on the bumper and it made the noise turned out to be a bolt loose and if you wiggled it just right it made noise.

 

[JetBlackNali]

Check for loose bolts on all suspension mounting points. Sway bar mounts (rubber maybe hard or ovaled) and end link play. Track bar mounts. Or could even be exhaust touching something. Hope this helps.