Noise while driving

[Runaround]

I have a whining/screaming noise coming from my truck. I can’t determine where it is coming from. I know it isn’t engine related because it doesn’t change sound with rpm only speed. It makes the noise going down the road and if I coast in neutral the noise only changes as speed decreases.
I changed one front wheel hub thinking that was yhe problem, no change so I put that one back on and moved the new one to the other side, still no change.
I tried putting the rear on jack stands but the traction control system won’t let me get any speed. I pushed the button on the dash but still can’t get any speed.
Any ideas on this noise or how to get speed while on jack stands?

 

[GTyankee]

check the fluid level in the differential(s)
sound carries along the frame

 

[04fxdwgi]

Perhaps brake pad too thin and the screamer is making noise, or a stone stuck behind brake rotor shield, or a bent shield hitting rotor?

 

[Runaround]

The differential fluid is right at the bottom of the filler hole.
The brake pads are only a few months old. I will check the shields this morning.
I’ve also read how to get the wheels to spin with speed while on jackstands, so I will do that today also.

 

[Runaround]

BTW thanks for the replies. I will be posting the results of what I find.

 

[18CrewDually]

Dry/bad U-joint perhaps. They can sometimes be difficult to locate a bad one until you disconnect the shaft and work the joint in all directions. It should be smooth & no play.

 

[Runaround]

U joints move freely in all directions, no rust coming out of the caps. The brake dust shields are not touching.
I pulled the driveshaft while on jack stands, ran the truck, no noise, so it must be a bearing in the rear end.
FYI this truck does have 194,000 miles on it but has been driven and serviced regularly with care by myself since it was about a year old and not abused or driven hard.

 

[Runaround]

I have given up and decided to bring it to a shop today. I’m waiting to hear from them.
This is the first time in my life that I have ever brought a vehicle in to a shop for repairs other than transmission rebuilds on some front wheel drives that my wife had in the past. Luckily now she is also driving a truck, a Dodge at that.

 

[GTyankee]

engine turns the transmission, which turns the drive shaft
which turns the Pinion Gear, which turns the Ring Gear.
Which in turn, turns the Carrier Bearings, which causes the right rear axle or if the carrier is LSD, to almost turn both rear axles to rotate in sequence, almost to the point of POSI-Traction

I wonder if there is a way to measure the carrier assembly for wear & tear

 

[Runaround]

The truck was diagnosed by a reputable shop that the gears are the main noise and also the pinion bearings are making some noise, so I was told a replacement differential would be needed.
Now I’m trying to get quotes for used differentials, rebuilt units and possibly buying another truck and selling this one as is.