I guys not sure if anyone can held I’m not by any means a mechanic! I’ve taken the engine out of my 2a and found oil leaking from my clutch withdrawal unit this looks to have been caused my a loose stud though whilst it was off I noticed the lay shaft castle nut is loose is there a way of tightening it without stripping the gearbox ? Iv tried putting in a gear but it just turns the shaft when I try to tighten!, any help would be greatly appreciated