Pinion nut torque and flange play

[Curious Hound]

Yes. Remove the cover and inspect everything. Only other things to check might be the wheel bearings.

 

[Shran]

Kinda hard to explain without being there but if the pinion turns freely and there's no slop there, in theory, that would eliminate that area. You're not gonna be able to see much if you pull the cover but you could at least inspect the oil for metal shavings. Both pinion bearings are hidden inside the axle housing and can't be seen without actually removing the pinion gear itself.

One other thing to check would be the slip yoke on your driveshaft... if it's got a lot of slop in any direction other than the in-out movement that it's designed for, your noise could be coming from that. A little slop is OK... a lot is not.

 

[alwaysFlOoReD]

There might be brinelling in the pinion bearing races. Kind of like little grooves perpendicular to the way the bearing turns. If you remove the tires and driveshaft you might be able to feel it by turning the yoke by hand. You could also check this when you have the cover off. Take the c-clips off that hold the axles in and pull them out enough so you aren't turning them when you turn the yoke. This will take the axles out of the equation for bad bearings. If you do feel it then I would opt for a new used rear axle.
Edit; the only time I've seen brinelling is in u-joints on the crosses. Also I've had bad u-joints that were tight.
Thinking about your symptoms only showing when off the gas wants me to think the coast side of the ring and pinion.

 

[91stranger]

I know the pic isn't the greatest but the main gears looked perfect. No sharp edges, gouges or anything like that. My plan is to put the impact on the pinion nut again and see if that changes anything. If not, I've been trying to find a good rear end but haven't had too much luck other than ones that are $300 and up.

 

[pjtoledo]

now would be a good time for some marking compound

 

[91stranger]

now would be a good time for some marking compound

For what?

 

[alwaysFlOoReD]

For what?

Its a colored ink the you spread on the gears. Turn the gears and you can see how the teeth interact. I've never got that far with gearing in mechanics so can't help any more than that.

 

[Shran]

I don't think it's going to tell you much. It's used for setting up gears, it would give you an idea of their contact pattern but it won't help find a bearing noise.

 

[19Walt93]

If the noise changes with throttle pressure it's probably pinion bearings, carrier bearings would change with speed and wheel bearings would change with speed and when swerving left to right to load the bearings. If it need any bearings change them all because they're all running in the same gear oil and metal particles from the failed bearing are floating in it, also thoroughly clean out the housing before reassembling. If you change only some of the bearings and have to take it apart again next month remember: I told you so.