If you have manual locking hubs (if not, you can buy them easy) yeah you could run a typical 4WD front axle with the transfer case engaged and hubs unlocked but other then frequent off-road use, why would you wish do so?

 

 

Not really. When the 4WD acutator locks up on the street you will know it, You turns will be thumping the whole vehicle. Mine when out at 110.000 miles and many years.

They are really easy to replace, at least on a GMT-400. Unscrew the old one, chuck it, put never-seize on the threads and dielectric grease on the connector and you are good to go.

You can buy locking hubs, like Warn's, the best on the market, but those will run you over $200 dollars and lots of time to do it right if you are really into off-roading, incluing deep water crossings.