I think I lost my 4wd lock isn’t working anymore. At least the light isn’t coming on saying it’s locked. Can this be regained by adjusting the shift box or is it something else?
Yes, it could be from all the use yesterday on the inclines they could use some adjustment. Always best to try and shift modes before getting in a pickle or after so there is least amount of strain on the engagement components as well as the cable actuation system.
However a trick that works often is go from 2WD or Turf mode into just 4WD, once that indicator is set only then shift over to 4WD Lock. Also that dash indicator just doesn't instantly change, it requires movement in order to physically work inside the differentials. When I go to Turf mode, it sometimes takes a couple of minutes to indicate unlocking rear differential, but it always does.
In all honesty, nothing we were in yesterday afternoon makes a difference, locking up the front end in those situations just makes it harder to maneuver around rocks & ruts. The wet slick mud on the rocks was the problem, regular 4WD is your best option 95% of the time.
That said there is a few good threads on here on correctly adjusting the cable box, a little goes a long way and too much adjustment can negatively affect the other drive modes.