Fzj80 4wd, centre diff isues

[Jaiman]

Hi, i have a 1993 fzj80, the isue it's that the centre diff fork gets stuck on off and the actuator can't bring ir back,i can hear the motor actuator worlking, but nothing happens, so my mechanic did take down the transfercase for clutch mainteinance, taking advantage of that we unstucked the fork and it worked some times since that, but last Time it got stucked again.

I got some cuestions for you guys, 1: how does work those cable adaptations, 2: it's there any way of unstucking the fork without bringing the transfercase down.
Thanks for your atention, sorry if any missunderstunding, english it's not my native lenguage as you can see, Also what Is the function of this ?

 

[Jaiman]

 

[shocktower]

I am pretty sure if it is free, but does not want to unlock, you can try backing up on hard ground and it should unstick it, and I mean back up 20-30 meters stop and then try to unlock, it may take a few tries but it should , Good luck