One problem related to axle shaft seal has been reported for the 2006 Nissan Xterra. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Nissan Xterra based on all problems reported for the 2006 Xterra.
Rear axle seals leaking; replaced left side on 7/19/07 at 24006 miles; replaced right side on 8/25/07 at 27278 miles; replaced right side again on 4/15/08 at 48274 miles. Gear oil leaks pass seal onto brakes, rotors, and tire.