I was launching a boat today in my Xterra (01, auto, 4x4, V6). I had it in 4 hi putting around the ramp, but before I backed into the ramp, I decided to put it in 4 low just to make sure I had plenty of power coming back up the ramp. I stopped, put it in neutral and shifted to 4 low no problem. Then I put it in reverse and went to back up and it made a horrific noise, I guess you could call it a grinding noise, and the ATP light came on. Somewhere during that ordeal I instinctively yanked it out of 4 low back to 4 hi. I thought I just destroyed my car but luckily it seemed to work fine and I proceeded to launch the boat, pick it up, and drive 30 miles home (after putting it back into 2hi and unlocking the autohubs), however Im still curious WTF happened. My friends say since I had the wheels turned a lot (steering wheel almost locked), that 4 low locks everything and that caused the noise (something like that). Is this true/can someone explain more? Is my transfer case going to explode when I drop it in 4 low next time? This is probably a dumb question(s) but Im a 4x4 noob and like to know whats going on with my vehicle. Thanks

Are you sure it was all the way in 4lo? Often times when shifting between 2wd and 4wd if you don't do it quick enough you'll get a little grinding. If you are in neutral when shifting, you won't hear it until you put it in gear. You may want to try putting it in 4lo at the house and see what happens. Make sure you push down on the shifter and pull it into 4lo as far as it will go.

The grinding noise you hear are the transfer case gears not lining up properly. It has nothing to do with the steering.

-Michael

Lesson learned - concrete landing and launching a boat = bad time for 4wd...

especially with:



When in 4WD, the wheels have to be able to slip some. (Outside wheels on a curve travel further than inside wheels.)

Chock it up to a lesson learned. I also agree that you should now try it in your driveway WITH THE WHEELS STRAIGHT, just to make sure nothing is blown/destroyed (highly doubtful).

-G