This is something I wish I had known before I installed my 'reconditioned' LT77!!!
My 5 speed box worked for about 5000 miles, before coming to a crunching halt. Quite literally!
Inspection revealed that the internal oil pump hadn't been fitted correctly. As a consequence of which the box had been running virtually bone dry the whole time, surviving on 'splash oiling' alone. Here's a pic of what that oil pump looks like, and some snaps showing what my mechanic removed from mine when we investigated the fault!
Don't fit one of these boxes without doing this simple check before installation!