Disaster????

Howdy folk

Just got back from a week long solo trip (with a mate in the car with me!) to the Far West Coast of SA, fishing and camping. Had a great time, but had an incident in which I am hoping some of you can put my mind at rest instead of me keeping the sick feeling in my stomach at the moment.

What happened was we were in 4wd on a sandy track from the beach to Yalata Roadhouse. Got there, re-inflated tyres, turned hubs to 'FREE' and drove away none the wiser that the Jackaroo was still in 4wd (or the lever at least) Thought I could hear a humming sound at 100kph, but thought it must just be the fan as we were fairly loaded and was a warm day. Fuel consumption was worse than normal after half a tank. Got to our destination to camp (about 320 km from Yalata) and realised the trans lever was in 4h. Looked in the book to confirm my worst thoughts and it said not to driver over 5km/h or 100m in 4wd with hubs in free position.

QUESTION - what damage if any have I done. Will it be immediate (haven't tried in 4wd yet) or will something go wrong in 3 yrs when warranty runs out? What parts will have been damaged?

My first thoughts are that the front axle is turning like when you are in 4wd, but because the hubs are in free position there will be friction as the grease burns out in the hubs, possibly leading to hub wear. Might be wrong though. Your thoughts appreciated. Please be gentle! (P.S. didn't want to ask my mechanic in case the warranty company speak to him on the sly if I eventually put in a claim)