Hi Geobay, the ZF manual might give you a few clues but I can’t guarantee it. One indicator of era/ year of manufacture might be the major change with the output flange, I’ve never seen one where the output flange was secured by a big nut, .....only what I assume were the early model where I had to split the
gear case and press apart the entire lower assembly to get to the seal and was surprised to see a thread on this forum about the user friendly version. And here’s a tip, when you get the mainshaft out, make sure you replace the two
bronze faced thrust washers and either inspect or replace the big shock absorbing dished washers, often they go un noticed and un inspected in a
rebuild.