Rear wheel bearing noise??? any help would be much appreciated

[MysticMac]

Hey guys . I have a 2005 LS6 and just the other day i noticed a humming noise coming from the back rear wheels (right side)
I put the rear of the car on jack stands so the wheels are off the ground.. I put it in neautral and moved the tired up and down (6-12 o clock) and there is no movement at all on either tires.. now am i doing something wrong? i heard if theres a bit of resistance when in neautral that means it could be the bearings.. now im not sure exactly... where Joegr at ? lol

 

[joegr]

Are you sure it is the right rear? Since you have the back wheels off the ground, you could disable AdvanceTrac or traction control (whichever you have) and put it drive. I wouldn't go over 50 MPH on the speedometer (one wheel could be doing 100 MPH). See if hear the hum and if you can better locate it. (Note that is is probably normal for one wheel to spin faster than the other.)
If it's still the rear, then it probably is the bearing. It could be the CV joint, but I think those usually click.

When my front bearing starting roaring, it still had no play (but it did feel crunchy when spinning it by hand after removing the wheel and the rotor).

 

[LS4me]

Hey guys . I have a 2005 LS6 and just the other day i noticed a humming noise coming from the back rear wheels (right side)
I put the rear of the car on jack stands so the wheels are off the ground.. I put it in neautral and moved the tired up and down (6-12 o clock) and there is no movement at all on either tires.. now am i doing something wrong? i heard if theres a bit of resistance when in neautral that means it could be the bearings.. now im not sure exactly... where Joegr at ? lol

Mine was the pinion bearing....

 

[don-ohio]

What JoeGR said was same on MY front bearing assembly. Quote: `When my front bearing starting roaring, it still had no play (but it did feel crunchy when spinning it by hand after removing the wheel and the rotor).'

Undetectable play in the bad bearing. Just when removing the tire and rolling it slowly could I feel the slight roughness.
I was gonna ask if you checked the level of rear end(differential) oil ? don-ohio

 

[MysticMac]

how do i check the rear diff fluid?

 

[don-ohio]

There's a plug in the punkin(differential) that probably takes a 3/8" square drive,or ordinary ratchet extension to turn it.I'm not remembering if it's on the front of the punkin or the rear.You'll find it.
When you remove the plug,fluid should either run out or you can stick your pinky in the hole and touch the fluid. Shouldn't be only about 1/2" lower than the hole.If it is, top it up til it runs out. don-ohio ^)

 

[Telco]

There's a plug in the punkin(differential) that probably takes a 3/8" square drive,or ordinary ratchet extension to turn it.I'm not remembering if it's on the front of the punkin or the rear.You'll find it.
When you remove the plug,fluid should either run out or you can stick your pinky in the hole and touch the fluid. Shouldn't be only about 1/2" lower than the hole.If it is, top it up til it runs out. don-ohio ^)

A bit of clarification - the plug is towards the TOP of the differential. If there is one on the bottom (I haven't looked in a while) that one will be the drain plug, but it's in the side so one not familiar with it might assume that it just doesn't hold a lot.

 

[oddball]

No drain plug on these (at least Gen 1 for certain). You get to remove old fluid by pumping or significant disassembly of the rear subframe.