A buddy of mine just bought a 1999 ranger, that has the auto locking hubs at the push of a button, how do you operate them? His truck came with no owners manual. Are they electric or vacuum at the wheel? And do you have to be in park or neutral, or can you shift in and out anytime into four wheel drive even while moving. Do you have to go in reverse to take it out? I have a 89 Bronco that has self locking hubs, im lost on the more modern ones.