To be honest, I haven't changed the oil. The gear started jumping out one day and never looked back. Even if you hold it in gear it jumps out. I guess the 1st gear baulk ring has fractured, but she can't afford to have the TJ off the road while we wait for USA shipments.
Surely ever other Birty has a spare gearbox lurking at the back of their sheds, come on guys, you don't understand the grief I am getting from daughter and mother!!
Regards,
Tim.