After doing a search and reading my manual, I still have a ? about this 4wd stuff. No driving in 4wd on pavement...do conditions such as snow depth or amount of mud determine amount of time in 4wd. Then what is the purpose of 4wd if you are only going to be able to use it "off road"?
I don't have any experience w/4wd but I know people that have blazers or explorers and they can keep the truck in 4 high all the time. Does the X have a different type of 4wd then the others? Thanks

Keeping your truck in 4wd continously does a couple of things. One it will ruin your gas mileage. Two it will ruin the transfer case and front differential. The Xterra's 4wd is not made for running on dry pavement. The outside tire needs to slip a bit on turns otherwise it will bind up and be very hard to steer and you will hear parts breaking. Don't do it. I will occassionaly put my truck in 4 Hi on dry pavement for a short period of time in a straight line to make sure the seals stay moist but don't even attempt turning it. This should all be in your owners manual.

Yeah, the X is a 'real' 4x4. If a vehicle is able to run in 4x4 full-time it really is an AWD system rather than a 4x4 system. Using 4x4 on dry pavement is pointless as you should have all the traction you need unless you enjoy climbing over high curbs and whatnot.

You can use 4x4 anytime you want but you must ensure that the tires are able to slip when needed. For example, I was driving through some woods, making my own trail really, making very tight turns and on several occasions you could hear and feel the rear tires slipping slightly to catch up with the fronts. If I was doing this on dry pavement, the pressure would have to go somewhere as the tires would not be able to slip. Thus parts break. As for keeping the seals from drying out, every month I lock the hubs (engage 4x4) and then disengage 4x4, leaving the hubs locked. This way you can drive just as normal as ever while 'wetting' the seals and moving various other parts to keep them in shape.

And yes this is detailed in your owners manual as well as this website (search) and many other websites. Where do you think I learned about 4x4s? My X is my first 4x4 also.

Despite the various marketing campaigns designed to mess with your head (AWD, 4WD, Full time 4wd, part time 4wd, quadra trac, blah blah blah) there are only two types to concern yourself with. The drivetrain designed at the factory from the bottom up to drive all 4 wheels at the same time all the time, and the type that was NOT.

The 4x4 system and manual transfer case in the Xterra is more "inconvenient" from a marketing standpoint because the driver has to make decisions and actually implement the system at various times and in various conditions. We like it because we as drivers get to make the decisions and actually implement the system at various times and in various conditions!

The advantages are gas mileage (as Scott pointed out) and more torque can be generated at each wheel with the "old fashioned" transfer case method.

"Depth" of snow or mud has nothing to do with when you decide to go 4-hi or 4-low. If its "slippery" out, shift into 4! If its dry and your tires have maximum traction, don't. All you need is enough slip between your tires and the pavement (or dirt, mud, whatever) to allow your outside tire to spin a bit to overcome the differential.

There's a loose gravelly road near my house where I go once a week to keep the seals good. Usually on my way to the car wash!

Thanks to all with your insights. I was just confused with the types of 4wd offered by other manufacturers.

I thought once you start driving at highway speeds again, you are not suppose to leave your hubs locked (even though you are in 2Hi)? Doesn't that cause rattle and wear on the hubs? At least that seems to be what people have posted on this website.

Well obviously leaving the hubs locked causes more wear on parts you would not normally have to use. However, you should not hear any rattle or clicking coming from the hubs. I only heard that once when shifting to 4H going up a steep incline. The hubs could not lock b/c of the pressure alread present on the wheel. I have driven on the highway in 4H due to snow, the stock Grabbers suck big time. Your drivetrain should be just fine.

You own these woods? If you don't, that is not a good thing to go around boasting about. Pretty soon you'll get a big "SUV = Death" bumper sticker slapped on your vehicle.

Leave the trailmaking to the loggers and power companies...

I don't own these woods but my Grandfather does. He owns about 18 acres of land and there are trails, sort of. Originally, there were trails as he was back in the woods a lot but the trails have grown over a bit. That is what I meant about making my own trails. Does that make any sense?

The "wear" on the front driveline components is negligible and is no different than the "wear" than is put on an AWD of FWD vehicle. Differeentials are differentials and CV joints are CV joints, all designed for a 100% duty cycle.

Brent