Loud grinding scraping noise?

[Zuke]

03 V8 4x4 here and yesterday on my ride home I noticed an odd noise. It almost sounds like there is a tree branch/stick dragging under the truck as I drive down the road. The noise is not constant and seems to stop when going over bumps or small hills. It almost sounds like an steam locomotive but it stops intermittently. It does have a minor metal ring to it. It makes the noise at low speeds and highway speeds.

I checked under the truck when I got home and found nothing hanging or broken. On my drive in to work today the noise was there and I noticed when taking sweeping right hand on-ramps or corners the noise grew louder. Left hand corners it still makes the noise but doesn't get any louder. It sounds more like its coming from the center to rear of the truck.

My first thought was a heat shield/skid plate hitting the drive shaft or the tire but everything looks ok.

Any thoughts?

 

[WXman]

Are you sure the brakes are all OK?

 

[Zuke]

Are you sure the brakes are all OK?

It could be a brake issue but there is no drag when accelerating and the brake rotor temp is normal. I have had frozen calipers before. The brakes are functioning like normal. I never checked the Parking brake though...

 

[mikebontoft]

you might want to check the backing plates of your brake rotors. Also check for any loose heat shields you may have missed. Odd noises like this are incredibly hard to figure out over text.

 

[Gatafly]

Also check for any broken parking brake parts inside the rear disc. My bet is that is where the issue is.

 

[WXman]

Also check for any broken parking brake parts inside the rear disc. My bet is that is where the issue is.

I've actually had this happen before on a Jeep Liberty. Rear brakes were designed the same as the 4R though. When I pulled the rear discs off, the parking brake literally fell onto the ground as crumbles. After replaced, it solved my noises.

 

[Bastone]

I've actually had this happen before on a Jeep Liberty. Rear brakes were designed the same as the 4R though. When I pulled the rear discs off, the parking brake literally fell onto the ground as crumbles. After replaced, it solved my noises.

The EXACT same thing happened to me when I pulled my rear brakes off to upgrade. Just crumbled out.

I would definitely have your rear brakes fully inspected, and make sure you check all heatshields under your rig. This past January, I had a sound that was similar to what you're describing and it ended up being the heatshield above the muffler that got loose and was rubbing on the driveshaft.

 

[M1911]

That sounds very much like what my truck sounded when a heat shield rusted through near the bolts.

 

[Zuke]

Thanks for the suggestions. Looks like heat shield will be my first place to check then followed by rear brakes.

 

[NJshadow93]

How are your CV axles? Any grease visible around the boots? Is there play in the axles? They could be going bad.

 

[avionics]

similar problem here...once I was able to get under the truck found exhaust heat shield was rubbing on driveshaft...removed heat shield noise gone

when I gat a chance will drill new holes and re-install

 

[Zuke]

Thank you all. I managed to sneak some extra time at lunch and crawled under my truck. As many suggested it was the heat shield above the muffler. The mounting holes had rotted through and it was just resting on top of the muffler and hitting the drive shaft. I removed it and the noise is gone.