Outer Limits 4x4 Board

How do i know if I have a vacuum operated (push button) gearbox or not?

Lost use of 1st and 2nd gear, kinda kangaroo hops if in gear.

think I need a new gearbox, unless others have ideas.

I have a 1987 (Jan) fj62 Landcruiser 5speed Petrol Model.

the vac operation was only for 4wd you would know the cor would have a straight shift 4wd lever like a patrol and a 4wd button on the rhs of steer colum