I was going to state exactly this.
I had the same noise that went away with the clutch in. Was the front bearing. Trans was fine until it wasn't. I was running 75wt gear oil and the bearing noise was awful.
When bearings make noise, they're a problem. Bearings fail due to fatigue and will start to shed very sharp steel into the oil.
My first experiences inside a transmission were fwd 5spds. These 833s are cake in comparison. So easy to rebuild. Order the whole kit from a place like brewers and get their alignment rod. Makes it so easy that there's no excuse to avoid the full rebuild.
Getting the reverse gear out was the toughest part for me, but a section of pipe and some nuts, bolts, and washers made for an quick press-out fixture. Was super easy to clean all the guts to perfection too.