driveline grinding noise. HELP!!!!

guys, i did my u-joints before the slamology show, it drove great 650 miles there and 650 home, and i have always had like a binding noise when i am not on the gas i just chocked that up as something that i had to deal with with a bagged truck. on to my question now i am getting like a metal grinding noise that happens not nesisarily under load but only from 5-40mph anyone know what causes this? my carrier bearing is solid.......any ideas?????????????? <img src="{SMILIES_PATH}/icon_confused.gif" alt=":?" title="Confused" />

Are there any physical marks on the driveshaft? Sounds like the u joints are coming loose to me but hard to say.

Baha, i just ran out there to check and the u-joints look fine and the driveshaft felt tight......
i wonder if i should drain the tranny fluid and do a new filter just so i can see if its internal...

rear pinion? how high is your ride heigth? tryin driving with the truck fully lifted. then with it at ride heigth.

So once you get above 40mph the noise stops? Is there any vibration? Just as a test could you put it in neutral once you get to the speed that makes the noise and see if it's still there. A friend of mine has a similar issue but he had vibration. What the problem turned out to be was the drive shaft wasn't balanced and the u joints were loose lol

I'm sure you check the fluid level right? Just trying to help eliminate the basics. So many times when I have an issue it's the basic thing all the time like a line disconnected or loose lol

like he said, check the pinion. had a problem like that before i redid mine when i was at full height.

there may be a little vibration but i dont really notice it till around 70 mph
also, it does not matter if its in gear or not, if i am rolling its making the noise..

sounds like your drive shaft is being pushed into your trans. Does it happen at all ride heights? A slip/spline added to your driveshaft will help. Drastic pinion angle change can also push in your driveshaft and cause vibration.
this video shows a good example of different setups and what happens to your rearend.

Hawaiian,
that could be, it gets worse the lower or higher that i go..... where can i get one of those slip/ spline deals other than the one that came factory on the truck?

It may NOT work if your setup has drastic pinion angle change when going up and down. you can see how it changes in the video clip. The slip spline will help with the driveshaft going in and out. you can check with your local 4x4 store or look for a driveline shop in your area.
looks like this. 4 wheelers use them.