Hey everyone - noOb here.
I've got a tremendous noise coming from the rear of my Jeep that I am trying to diagnose. It almost sounds like a growling noise, both when the Jeep is under load or engine braking. It makes this noise whether I am in gear, or in neutral while coasting.
Recently changed the fluid in the differentials and TC thinking that may help, no difference. I took the cover off of the rear diff, sprayed it all out with brake cleaner, and refilled with Lucas Synthetic 75W-90 gear oil. I checked it a week later, fluid is still topped off (no leaks).
So, now I am trying to narrow down other items in hopes that it isn't my gears. Climbing around, I noted that there is some rotational play in the drive shafts, and wasn't too sure if they should be this loose. They wouldn't move any other way than rotating - tight on all other planes.
I've made a video (sorry for potato quality) and uploaded it to give more explanation.
Any feedback/suggestions/help is appreciated.
4.88 gears, ARB airlocker in rear.