One problem related to transmission noise has been reported for the 2008 Nissan Xterra. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Nissan Xterra based on all problems reported for the 2008 Xterra.
Timing chain noise upon starting engine getting vibrations and noise--similar to speed bumps on roadway-- in vehicle drive train around 40 to 50 mph (transmission?).