Zetor 7245

I bought a Zetor 7245 that runs well motor wise, good hydraulics only the brakes didn't work. Pulled off the rear wheels and final drives? and repaired the brakes. Put back together alls good EXCEPT it won't drive in two wheel drive. In for wheel drive the front wheels drive however if you lift the front wheels off the ground there is no drive. The PTO all works as well.
My question is, is this the result of something we have done or would it have been like that when I bought it? (I didn't check)
Also what would I have to do to repair it? By the way I'm only a backyard mechanic.

Hi

I don't think it's anything you've done as the only part you could have disturbed is the diff lock sleeve and it should still drive even if you've knocked the 2 pivot pins out. Try it with the diff lock pushed down. If it drives then you've probably got a broken halfshaft. If still no drive then it's likely the rivets which hold the crown wheel onto the diff have sheared.

Good luck
Mike