Differential Fluid Change

I have looked in the maintenance section of my owners manual and can't find anything that tells me when the front and rear axle fluid (differentials) needs to be changed on my 2001 AWD Safari. It says that the fluid levels need to be checked and topped off periodically. Does this fluid need to be replaced and if so, when?

Thanks in advance.

I don't think so. What made you ask about this?

I have had service reps at two dealers tell me that the differential fluid needs to be change at 30,000 miles. One wanted about $130 and the other about $250 to change the fluids in both differentials (AWD). If it really needs to be done I will do it myself. How many of you have had this fluid replaced?

my 2000 astro according to the manual was to have the oil in both diffs changed at 80000kms. My dealer said the cost would be 275.00 canadian
I changed the oil in both in 40mins and at a cost of 27.00. The oil in the front was clean. and it was hard to tell with the back as you have to add in the diff additive that it requires for the lock up diff.

I have fought with the dealer ship for two years about a vibation that will not go away. It starts at about 80kms and continues all the way up.if anybody has had this and has a solution I sure could use the help.

Awd ??

Sounds like the shaft may need to be balanced....? I dunno!