Some background on my truck: puchased used in 06, dont know history prior to that. since purchased, i have done (or had done) the following...
brakes front & rear (w/rear cyls)
vp44
drive-line u-joints & carrier (rear joint 3x)
master cyl & hydro booster
new batts
blower motor & resistor
back-up lamp assy's
horn
driver frame-rail hard brake line
starter
rwss
front end (ball joints, track bar, steering stabilizer, sway bar end-links, tie rod end, hubs, axle ujoints, shocks)
Etc, Etc, I'm sure I've missed some...

Currently, I'm trying to diagnose whine or squeal from the rear (I think). It sounds like a bearing, but hard to hear over engine/road noise. Happens at speeds over about 25, in gear or out, accel or decel. From my research, sounds as if it could be front pinion bearing failing. Running Mobil 1 syn for lube, was changed maybe 20k mi ago.

Currently, I'm battling a bunch of other issues, most that need to be repaired asap. (heater core & evap leaking, e-brake cable frozen, fuel tank not venting properly, tailpipe MIA, blah blah blah...) These are just the most important needs right now, not including things like disintegrated dash, broken map lights, needy tail-gate latch, broken arm rest, rusted out doors, etc etc...

Sorry for the long drawn out post, but I have to wonder if I'm doing the right thing trying to keep up with all these repairs. The wife thinks I'm nuts, & the truck can cause some stress in the house because of all the $ & time spent on it. Will it pay off in the end? The truck is vital to me in my work, so that is basically the reason I've tried so far to keep up with mounting repair costs.

Thanks for any insight and help you can provide, it is greatly appreciated.

 

if the bearing has failed you should have a lot of slop in the front yoke (rear diff) I had my nut back off on the pinion, the dana70 does not have a crush sleeve and requires a stupid amount of torque, like 250-280ft/lbs, I used red lock tight (small amount ) and an impack to get it tight enough.
also a failed u-joint will cause a squeel, re-inspect the u-joints if you see any rust or rusty dust near any of the caps, that u-joint has failed even if you cant feel any play

 

Thanks for your response. I will def recheck the rear joint, i havent yet done that. I guess the pinion going bad could also be causing the rear joints to fail as well? I've done the rear joint 3x, but the others, including the carrier, only once.

 

Does it sound like this:
http://www.youtube.com/watch?v=rAkyI4r0IUE

 

Thanks for the video boney... I rechecked the rear u-joints, and checked for the noise in your video. The loose/spinning ring in your video is not the problem. It does sound similar to that, but the pitch is lower... Was that a part of your driveline that was damaged? I have that ring on my driveline, but it is fixed, and does not spin.

Initially i thought it was a bad front wheel bearing, as thats the sound im hearing. but after having the hubs replaced, the noise remains... I still need to drop the driveline and check for any play in the pinion...

Thanks for the suggestions so far, keep 'em coming... still trying to locate the problem...

 

The pinion bearing would be a high-pitched whine. A wheel bearing would be a lower-pitched growling noise. Try driving while swaying the steering wheel side to side (on a road with NO traffic of course!) If it's a wheel bearing the noise should get worse as the weight of the truck transfers to the bad bearing.

Hope this helps!