Sound From Underneath Rear, Almost like a Rattle

[dougger]

Ok, I have a noise, rattle, clunk that is bothering the heck out of me. I know it is not the famous clunk from the yoke or the pads missing on the leaf springs. I have even removed the Tailgate thinking that was the issue, but no it was not.

When driving on gravel roads or if I hit small bumps in the road I hear the noise and it sounds like it is coming from underneath and towards the rear of the truck. It is hard to explain the sound, but it almost sounds as if there was something loose and the metal is hitting again the frame?? I have 126000 miles on it, so I figured I would replace the shocks, they needed it and that did not help, it is still there.

Now the twist, when the temp outside gets below 60 the noise starts to fade away or I have to run over a bigger bump to hear it, and below 40 it almost does not exist. Now the hotter it gets out, the more I hear it and during the summer months it is really annoying.

I have also looked underneath and could not find anything that looked cracked, broke or loose. But I was hoping that someone out there has had this and fixed it or could lead me in a direction to get rid of it.

Thanks,

Doug

[j cAT]

the rear brake shields , also the park brake shoes.

possible that the muffler rubber supports are worn allowing too much movement.

[wannablast]

Mine is doing the same thing. It is a 2001 4wd ext cab. It's been doing it for several months. It has about 128k miles on it. I don't drive it except for towing a boat or small trailer. It made a very strange almost grinding noise the other day. I had the wife drive it up and down the drive while I was walking beside it to try and locate the noise. I put my hand on the tire while it was moving and I could feel a vibration that coincided with the noise. I removed my brakes/rotors and didn't see anything loose or any signs of rattle. I was spinning my axle and it didn't feel right. It felt like there was a problem inside the differential. I will have to remove the diff cover and see if I can see any damage. I'll reply again if I find the problem.

[j cAT]

Originally Posted by wannablast

Mine is doing the same thing. It is a 2001 4wd ext cab. It's been doing it for several months. It has about 128k miles on it. I don't drive it except for towing a boat or small trailer. It made a very strange almost grinding noise the other day. I had the wife drive it up and down the drive while I was walking beside it to try and locate the noise. I put my hand on the tire while it was moving and I could feel a vibration that coincided with the noise. I removed my brakes/rotors and didn't see anything loose or any signs of rattle. I was spinning my axle and it didn't feel right. It felt like there was a problem inside the differential. I will have to remove the diff cover and see if I can see any damage. I'll reply again if I find the problem.

the rear diff requires fluid replacement every 40,ooomi. the cover is removed to clean the diff / gears/ magnet/housing.

most all lube shops use the drain plug and refill then the damage begins. not at all uncommon for the diff to be with cracked teeth and worn pinion with the wrong fluid replacing proceedure and LUBE.