As you know, the x-box or combining box in a hook, same as in a 46 (Frog) connects forward and rear rotor transmissions so the blades are always in synch.
I was carrying an external load in '69 out of LZ English, Master caution lit up, x-box temp way up, x-box oil pressure way down. Trouble!!
Punched off the external load and made a maximum effort descent. I focused on a dark green spot for some reason and when I flared, discovered it to be a canal overgrown with weeds.
I asked the flight engineer if we had 10 seconds to move it to the right. He is 40 feet back where the action was and he replied "Sir, put it down"
Remembering that the hook will float I put it into the water. I forgot the hatch to the cargo hook was still open and sure enough the CH-47 proceeded to sink right there.
We shut down and climbed on top and were soon rescued by a slick. A couple of days later, a CH-54 Skycrane came and drug it out of the canal where it drained water until it was light enough for the ride home.
Maintenance later told me one of the shafts in the X-box was crystallized, meaning it was red hot and ready to let go
So Yes, i survived a failure of the combining transmission failure by seconds.
All this to say "So what if the transmissions on the Osprey are linked, things can and will go south in a hurry!"
“...one of the shafts in the X-box was crystallized, meaning it was red hot and ready to let go...”
Wasn’t your time yet, Someone was watching over you.
What caused the fluid leak? Glad you made it.