Hi again. The bevel gears' there are 4 of them, run inside a cage which is bolted (or otherwise fixed) to the differential crown wheel. Two, one on either side, of the bevel gears are mounted on the driveshafts which go to the wheels. The other two bevel gears are mounted, free running, on a pinion shaft which is fixed to the diff cage. There are some very good You Tube videos which describe how it all operates. If both wheels are off the ground then turning one wheel will turn the bevel gear connected to it which will cause both the free running bevel gears in the diff cage to rotate thus driving the bevel gear connected on the other side of the diff cage
Don't forget to let us know how it all turns out though won't you because it all adds to our knowledge base even if it's not "happy news"'
all the best
Jock