Had the same problem when a rear wheel bearing was on the way out. Enough movement that the sensor was missing the pickup notchs . New bearing fixed my problem.

N Z new D/C hiluxs had 4.5 diffs imports have 4.3 .

The next road to river bed is Weedons Ross Road about 10 minutes west of mcleans island. You can go all the way to the gorge from there . Going back towards town is more of a challenge as you have to cross the main stream and the river is bit narrower from there onwards and you are talking jet boat ...