awd problem with my 2004 gmc envoy xuv?

[the wisdom bank]

when i place the selector into awd on my vehicle, it tends to make a slight friction/grinding noise while driving. This happens on both snow and dry surfaces. its seems to be worse while turning. Could this be due to a needed fluid change in either the front front axle or transfer case? are there any likely problems other than a needed fluid change??

 

[pedro7of9]

most people neglect service of drive systems..that said
1 CV joint bad
2 low/no fluid in front/rear dif or transfer case
3 clutches in dif,,chattering [common problem GM has a addivitive for it [posi sdditive] parts dept.