I just bought my first 4X4, and it is a used xterra, 2002 SE / SC. I am so confused with the manual book in regarding to engaging the 4hi. It talks about something of locking hub, etc...I am so confused. Can I put the vehicle to 4hi while driving? And what speed should I not exceed?

Check THIS THREAD

There is a lot of discussion and even a video showing the proper way to shift. (yes, you can shift into 4 HIGH while driving 25MPH or SLOWER. 4 LOW requires stopping and putting the truck in neutral)

Please tell me about the Automatic Hub Cap? Do I have to do anything to it before I engage in 4hi. And last night I threw it into 4low and I was not in neutral. I hope I did not break anything.

oh yeah...and what is the maximum speed I can go while in 4hi?

no max speed really in 4hi but if conditions require 4wd then you prolly shouldnt be going that fast anyways, you dont have to do anything for the auto hubs, all you have to do is after you go back into 2wd, reverse 4-5 feet to unlock the hubs (you can usually hear a click on either side if its quiet) personally i usually stop or stay below 5mph, depress the clutch and shift into 4hi, and for 4 lo, clutch in and shift into 4lo (mines a 5spd, if yours isnt then shift into neutral, i doubt you damaged anything by not being in N but i think its good practice to shift to Neutral before shifting to 4lo, also look above your passenger side visor, and youll see instructions on using the 4wd...hope that helps

A brief description of locking hubs (by someone who *thinks* he understands them): When you put your truck into 4WD, two things happen. First, power is sent to the front driveshaft by the transfer case (the thing with the 4WD lever sticking out of it). The front driveshaft starts spinning, which spins the front differential, and then the two front axle shafts (also called half shafts).

Locking (and unlocking) hubs are used to connect the spinning front drive axles to your wheels so that they will be powered. As soon as the axle shafts start spinning, the auto hubs lock the wheel to the axles - and voila! The front wheels start receiving power.

Some vehicles don't have locking and unlocking hubs - they are just locked all the time, which forces all of the front driveline to spin even when you're not in 4WD. Other vehicles (mostly older ones and modified newer ones) have manual locking hubs where you have to actually get out of the truck and twist them to lock them. This is a PITA (pain in the ass) but they are stronger than the stock auto ones and won't come unlocked accidentally

With auto hubs - that's it. They engage automatically. The only thing to remember is to back up several feet after taking it OUT of 4WD so that the hubs will unlock (if you listen VERY closely while starting to back up you can hear them go click-click as they unlock). The reason you can't shift into 4HI faster than 25mph or so is that it places too much stress on the hubs to go into the locked position at that high a speed and could break them.

You probably didn't hurt anything by shifting into 4LO with what you did - but do it in Neutral while completely stopped from now on... it is easier on the truck.

Speed in 4HI - there is no limit on how fast you can drive in 4HI vehicle-wise (though intelligence should limit you ). The REALLY IMPORTANT thing to know is when to use 4WD and when NOT to use 4WD. Never use it on paved roads (unless you're in several inches of water or other extenuating circumstances). The tires HAVE to be able to slip when you make turns in 4WD. If you're on pavement and turn, tremendous stress if placed on the driveline and it can potentially break.

do not use 4wd on dry pavement.

Pull down the driver side visor...there's instructions there.

Thank you very much for the information. I love my Xterra. Thinking of personalizing it more though. Any suggestions.

Yeah... mod it up so you can take it somewhere like this:


(actually it could go there now as a stock 4WD (Engineer Mountain road in Ouray, CO) - but mine looks cooler :p