So I have a 2003 X with the KA24DE motor in it with a 5 speed manual transmission, and the other day it started to act up. When it started to act up it sounded like gears catching as if there where some teeth missing and it sounds like its comming from the rear of my Xterra. I can also feel it in the shifter knob when it makes the sound. I know it's not the transmission itself because I am able to drive and it will go without any issues. Its just the noise is bugging the hell out of me. what do you guys think it is? Also im curious to know about rear axle swaps, how difficalt is it? how long does it usually take to do the swap? And what gearing ratio do you guys have? I am curious to know due to the fact that I have had toughts of doing it, but aint got a clue where to start and all.