FWIW: Our family wagon GU auto hubs were absolutely perfect for our past needs staying in cab without switching between school runs down the short highway and then feeding horses out in the wet paddocks on the way up to home. Smashed some of Tasmania’s iconic west coastal tracks too by locking them in for strength when needed. Their only downfall found that I never believed could but did oneday eventually happen was stubbornly continuing to run gear oil in its transfer case like its original era manuals stated. Auto transmission fluid is lighter and found needed in later manuals for GU auto hubs. The thicker transfer case gear oil of old will slightly rotate your front tailshaft just enough to spook the auto hubs into lock.
EDIT/Disclaimer: Please do check other threads I kindly learned off here too and your updated manuals beyond your 1999 edition
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