Tim 
2005 Nissan Titan King Cab 4dr King Cab SE 4WD SB (5.6L 8cyl 5A)
Differential Problems
 The ability of the 2005 Nissan Titan to tow was what caused me to purchase the vehcile.  The 5 speed transmission does an excellent job of towing a 4,800 lbs boat.  However, at 75,000 the rear differential developed a noise, which required its total replacement.  It wasn't a failure of one or two parts, but a complete failure where an entirely new differential was put in.  The rear end appears to be undersized as I changed the fluid every 20,000 to 24,000 miles which exceeds the maintenance requirement.  The dealer has replaced 2 or 3 others all around 60,000.  I talked with the dealer and Nissan who said it was out of warranty so tough luck.  This truck can't be counted on to hold up!!!