Now that I got your attention. I have a rumbling, grumbling sound and a vibration under a load. I have checked the u-joints and they seem to be fine, no loose motion. I decided to take the diff cover off to have a look see. Here are a few pictures of the gear set. It looks ok to me, what do you guys thing and what would be next? I have more pictures in my gallery and really large pictures if anyone wants a closer look see.

 

immediate thoughts are check the U joints on the drive shaft.

Did you do any work recent to the ring/pinion? If so did you check your back lash, carrier bearing, axle seals(unlikely)....

afterthoughts are stay away from your ladies starfish or it'll grind you up.

 

Indigestion. Give her a tums and she will fart it all out in the morning

 

The u-joints are tight, no up/down or rotational play.
That is the first time I have taken the diff cover off. I was hoping to find some kind of funky wear pattern.

 

Have you checked the T-case fluid? It's far enough back it can sound like the rear-end, or the slip yolk for that matter?

 

wheel bearings? they will grumble at you when they are going

 

You had the drive-line free, No park or Ebrake and surely found zero play? (between ears at the U-joint)

A u-joint that is dry and "going to go" might rumble and act up without much play, just a tad. If I climbed my hill with one like I'd bet it would be pretty warm! The cap.

 

Yup, yup. They can become sloppy when they fail, or they can bind up nice and tight. The only good way to check them is to disconnect them and work them around by hand.
Might also be bearings in the diff going bad. What did the fluid that came out look like? Didn't happen to lift it recently, did you?

 

I will take it out of gear and have another look at the u-joints. I have lifted it, still bone stock. The fluid had a light brown color to it. I opened the cover right after driving it 20 miles so the fluid would be warm and flow out easier. I could not feel any metal in the fluid and it did not have a silver cast to it. I had just checked the level and it was fine.
I have some trans fluid so I will change the transfer case fluid.
Thanks