You are absolutely right there, in the Patrol under "auto" slipping into 4H at speed is definitively not the ideal.
On mine, if I leave the front hubs locked, and drive on tar I can feel the drag of the sideshafts, diff, and front prop spinning, so I generally slow down to around 30-40Km/h before shifting into 4H. After reading what Brett said " auto free wheel hubs should not be engauged above about 10km/h ", I am going to reduce my speed down a lot !!! It makes sense that speeding everything up in a split second to engage is not the right thing to do !!
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