Good advice posted above!
Like Hemi stated: If new? The key is your First drain too be early (15k-25k) miles to get those break-in wear metals out. These are not beneficial to the clutch pack. If so equipt (limited/slip).
I drained mine @ the 10k mile mark & will again @ 25K then again @ 50K. It is a cheap/fast/easy service. If I towed more I would drain more often.
I have not drained the front yet! {Shame on me}. Will do after I get this transmission cooler kit installed.
Don't forget that oh so important transfer-case.