Could drive the cruiser hubs locked no probs, transfer case angaged,no probs but never ever engage them both on the tarmac.
if you have trouble dis-engaging, just reverse for a little bit to get the pressure off the drive line.
back to your Patrol, do as Aussie is doing, change ALL THE FLUIDS when funds allow. then you'll have a reference point for
service intervals. Still need those fuel prices please???
Also while you have it up on the hoist grab a large screwdriver and check all bushes.