rear axle/ diff problems

[The Doctor]

Not AE86, but i think there are enough experienced guys overhere who can help me with my problem

After some (unwanted) 'drifting' action a few days ago, my rear axle makes a terrible noise .

While 'cruising' it rattles (tried to capture it on a movie, but irl it's far more worse then this ). It's a metal to metalish sound.

When going full throttle, the rattling immediatly stops and my diff starts to whine (very loud). Sounds like a supercharged engine from the inside

I never heard any strange sounds from my axle untill that 'drift'action. And it suddenly came, being very loud.

I went to a garage to check some things.

- No abnormal play on driveshaft
- diff oil looked good, some minor bits of metal, but that's normal
- gearbox oil the same.

But the strange part was, when i ran it on axlestands, to try to find out where the sound comes from, the rattle was not coming from the diff, but it looked like coming from the driveshaft itself
Nearly impossible imho, because there are no moving parts other then the axle itself. Could be the gearbox, but i can't understand that (if the gearbox is broken) how it's possible to kill both the diff and the gearbox in the same time .

When i slightly pulled the e-brake, one wheel stopped and the pinion gears began rotating, i heard another sound. So i guess the diff is gone, but i can't explain the other strange rattle i'm having in my driveshaft

I was offered another KE20 axle, but i'm afraid it only solves one problem.

Anyone has some ideas for me?