Well, the transfer case has to be in 2hi of course with the hubs locked on pavement. I fyou aren't familiar with the 4wd system, ALL power goes through the transfercase at ALL times. It just splits the power to front and rear wheels when in 4wd. In 2wd, 100% goes to the rear wheels, but it is still through the t-case.
Now for manual hubs. With the hubs unlocked, and the t-case in 2wd, all power to rear wheels. Leave hubs unlocked, put t-case in 4wd:front driveshaft turns, front axles turn, but there is no resistance, because the hubs are unlocked, so its basically like driving in 2wd, except the front driveshaft is turning.
4wd, locked hubs, the power to the front wheels now HAS to turn the front wheel(s). Its as simple as that.
With the manual hubs, for instance, going over a mountain pass, where you know its snowing, but not sure if you need 4wd. Lock the hubs in, but leave it in 2hi. When and if you need 4wd, you just shift into 4wd. When the need for 4wd has disappeared, stop and unlock them. The only part I am not 100% sure of, is if the manual hubs allow you to shift on the fly while they are locked. Again I say yes, but I'm not sure.
With the hubs locked in, you ARE going to increase the wear on the front end, but realistically, if its mainly a street truck, you see what, maybe 5,000 miles out of 100,000 in 4wd? the front end is more than capable of holding up to wear from driving with the hubs locked in situations where they MIGHT be needed.
Dorian
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