fj62 manual stuck in 4WD after selecting low range and also pressing 4WD button

Should not make a difference. Sounds like the soleniod is stuck. On the 80# the actiator is held on with three bolts. some people have had success by cleaning up the contacts or whatever is inside with some electrical contact cleaner, reassembling and the refitting.

Also stating the obvious. Have you tried reversing up a bit with your wheels dead straight?
if you can't get it out of $WD then for the time being to avoid windup just set the free wheel hubs to unlock.

You will still be driving the tailshaft (unless you remove it) and the axles but you won't be driving the axles to get wind up.

I had to drive my 80# for a couple of months recently until I had the time to fit a new transfer box as I had a problem with the centre diff in that.

Even though mine is constant $WD the principle was the same. Removed the tailshaft and in my case the axles. Locke the transfer into 4wd and fooled it into driving.

David

Try backing it up a slight rise whilst trying to take it out of 4WD.

I've helped fix a couple of the actuators on 80 series, they seem to get minute cracks in the sealer where the wires go in and corrode which causes them to jam or not operate.
We managed to fix one but the other required replacement.

found the faulty to be the electric operated vacuum solenoid on the fire wall .price i $1000.00 but no longer available so fitted a solenoid off a cressida