Differentail noise....need help

[frontier]

hi,

i have commodore VY S 2003. when i drive up to 100km or above and slightly pull up foot from excellerator, i listen noise from the differential at the back..but if i keep pressing up i dont feel noise..

will any body tell me if its really from differential ? and if so, whats the problem with it and how to fix it ? do i need to change it . but i think this may cost and that what i dont want.

oil is always checked and its fine.

[Sabbath']

What type of noise is it? Is it a grinding noise, or a howling noise.

Is it an LSD Differential?

If it's a howling noise, it could be the preload bearing.