My truck started making a very loud whining in the rear axle. It’s loudest under acceleration and came on pretty quickly.
I took the cover of and the gears and backlash look fine. But with the wheels on the ground I can rock the carrier about an inch. Anyone have any Ideas on what the problem is.
The axle is 8.8 LS.

 

Loose pinion nut.
Try tightening it to 14-inch lbs of turning torque with the hubs off.

 

The slack is between the carrier the axles. I haven't properly checked the backlash yet, but I can't detect any movement between the carrier and the pinion, I have the drive shaft off and both wheels on the ground. The pinion moves with the carrier, the wheels/axles don’t move. I’m thinking it’s the axle splines and gears. Thanks

 

I do not think you understand what I am saying.
When you do not have the right pre-load on the pinion bearings the pinion alignment will move slightly. This results in a slight miss alignment of the pinion to the ring gear and this is the noise that you hear.

 

If I'm understanding this right, it sounds like you have a lot of play in the side/spider gears? Worn limited slip clutches will cause this because the thickness of the clutch pack determines the position of the side gear and how it meshes with the spider gear. When the clutches wear it lets the side gears move away from the spiders which increases the wear from them not being meshed tightly. An easy way to check this is to grab the axleshafts and see how much endplay they have. A little is probably normal but there shouldn't be much if the clutches are in good shape and shimmed correctly. It sounds like your limited slip needs rebuilt and you probably need a spider set as well.
That doesn't really explain the whining noise though. Try prying the carrier side to side in the housing to check for bad carrier bearings. Grab the pinion flange and see if there is any up and down movement. Also spin the pinion slowly and make sure it turns smoothly. I kind of suspect some worn bearings have let the ring and pinion pattern shift which would cause your noise.

 

You have bad pinion bearings most likely. Only way to repair is to replace the bearings in the axle. Not a novice job however. If you put the rear on jackstands you can get someone to "drive" the truck to speed and listen where exactly it is coming from.

 

Definitely the carrier bearings, the left bearing is gone, and the carrier is shot (removed the right bearing and it slips on and off the left side with no interference). The spider gears are chewed up pretty bad too, but the ring and pinion gear look fine.

I have an open carried does any one no if it will work?

 

Yes it will work you just will not have LS.
Put your old ring gear on the new carrier.
Make sure you use the shims that came out of your housing and make sure the one that came out of the left side goes back in the left side and so on.
Your backlash should be OK as long as you use these old shims.