My 2001 just started making a squeaking/scrubbing noise while its rolling. It's sounds basically the same on both sides of the truck. It doesn't seem to change in sound when you speed up or slow down. It also sounds the same while rolling in neutral. I tried putting it in 4wd and the sound is the same. I took both front wheels off and inspected the brakes thinking it kinda sounded like a squealer because a pad was thin. Brakes are good. It's got 260,000 miles. I am pretty sure the PO recently put new front hubs on it. Whats got me stumped is the sound seems the same on each side. I also thought it kinda sounded like an emergency brake cable rubbing on the driveshaft, if you can imagine what that would sound like. I'm not sure where to go from here. I'm thinking if it was a brake related issue I'd be able to isolate it on one side of the truck. If it was an engine issue I would be able to tell by revving it up. The automatic transmission was rebuilt about 3000 miles ago and it seems ok. I am not sure how to check the driveshaft (I'm thinking if it was the culprit it would change in sound as I speed up and slow down.) Any suggestions? Thank you, Mike

 

First thought is the carrier bearing. It supports the drive shaft and it's about mid-ship so it will sound the same on both sides. Give the driveshaft a wiggle and see if it flops around in there. Bring a strong light to inspect it. Could also be the E brake, the hardware is inside drums located inside the rear rotors and can get pretty crusty/inoperable. Maybe drive a few miles then feel around the carrier bearing and the rear rotors, whatever gets hot is suspect.

 

Thanks for the suggestions. I tried to record the noise. It's much more pronounced in the truck vs on the video but maybe it's enough to help. In the first video titled "Truck noise2" if you give it a few seconds to run you will hear it as I'm passing a tractor trailer. It's a slower speed than the other video, I think its easier to hear the noise.

 

It kind of sounds like a low brake pad sensor to me.

 

 

Haha... there are not enough tie wraps to support me under there! I got under the truck again today and found a metal plate rubbing agaist my exhaust pipe and thought that could be the culprit. Drove it and the noise is still there. I did do another video which I think captures the noise better than the others. You have to turn the sound all the way up and you can hear it pretty good. Thanks for the help.

 

Sounds like a bearing to me. Since it doesn't seem to change pitch/frequency with an RPM change we can rule out engine accesory/belt. Does it make the sound when you're sitting still - be it in nuetral or park?

 

 

Have you looked at rear brakes at all.

 

Since you say the brakes are fine, throw the entire truck on jack stands (or chock the front very well and just throw the rear on stands) and put your truck in neutral. This will allow you to turn the driveshaft by hand and/or have it rollover while idling and allow you or someone else to help id where on the truck it is loudest - be it front, middle, rear, etc.

 

 

Mike, from the OBS side your video's sounds like the exhaust down pipe rubbing on the passengers side fender weld area. I'm only saying this because I did the 3" down pipe upgrade on my 97 a few year ago and had same noises, and had to make more room for that 3" pipe to fit in that tight space. I know the SD's are different but it's worth checking out and don't know if you or someone else did an upgraded down pipe conversion.

 

Today I jacked the truck up and put it in gear. The noise is not present. This eliminates the driveshaft, rear running gear and rear brakes. Does the shaft going from the transfer case turn even when the truck is not in 4wd? I'm wondering if it could be a front drive shaft u-joint? It's got to be something in the running gear or something vibrating under the truck while it's rolling as it doesn't do it at all while the engine is revving or running for that matter as it was running / revving / idling while the rear was jacked up and in gear. This has me stumped..

 

front drive shaft will turn if hubs are engaged or your in 4wd otherwise no. you can check to see if one of the hubs is stuck engaged by turning the front axle shafts by hand. they should turn if your in 2wd