There's a TSB out on clicking from the rear axles (not specifically the diff).
http://www.infinitihelp.com/Ownership/Bulletins/Nissan/2004/NTB04-113.htm
How many miles on your current diff fluid? Other than changing out the diff fluid, I can't think of anything you could do on your own to fix this.
http://www.infinitihelp.com/Ownership/Bulletins/Nissan/2004/NTB04-113.htm
How many miles on your current diff fluid? Other than changing out the diff fluid, I can't think of anything you could do on your own to fix this.