Transmission swap failure

I have a 2002 z71 suburban, just got the engine
rebuilt. Right when we took it home from shop the
gears stop changing I realize the transmission
didn't have enought oil so thr mechanic added 5
quartz of transmission oil only t have the same
result my transmission failed. I have a sierra 2000
with the exact same transmission which I had
rebuilt a couple of months ago. Because I didn't
want to spend more in rebuilding another trans I
decided to switch trans, the sierra's trans was
working perfectly fine. So I installed the trans into
the suburban. I turn on the engine and it started
rught away, but I could hear a loud noise coming
from the trans, I checked the oil level and it needed
some but it was almost full. I took the truck for a
ride and not even two blocks away the loud noise
stopped and the gears stopped changing. I don't
know what went wrong....any ideas?