Need some help chasing front end whirring noise.

I am in the process of chasing a whirring noise in my front end.

This afternoon, I pulled the long, inner side axle shafts, and took the Jeep for a spin around the block without them. It was quiet. I popped it into 4 high (which it was resistant to do, making a grinding noise), and the whirring noise came back. So this affirms suggestions from another post that it is the gears or pinion bearing.

In working through this, before I pull the ring gear to see if is the pinion bearing I thought I would check the gear pattern as a possible casue of the noise. I don't know if these pics are good enough. I didn't have the usual yellow gear compound, but they had some prussion blue at Napa so I thought I would give it a try.

Thoughts?

Are you certain the noise is in the differential?

You said the Tcase made grinding noises when you put it in 4hi. Is the noise under the floorboard or out in front of you?

RedHeep said:

Are you certain the noise is in the differential?

You said the Tcase made grinding noises when you put it in 4hi. Is the noise under the floorboard or out in front of you?

Click to expand...

No, I am not certain the noise is in the diff, but that is what I it is looking like.

I realized after posting the t-case was grinding since normally the front driveshaft is spinning when 4hi gets engaged.