i have to replace bulkheads, anything i should check/lube?

[blueb8llz]

since im replacing the bulkheads, should i open up the diffs? my emaxx 3905 is about 3 months old but its been in the water quite a few times but runs fine. should i open up the diffs anyways to see if everything is in working order? what should i check for once im in there, and where do i lube and how much? all i have is team associated stealth diff lube and black grease, will that work just fine? sorry for the questions, i have never opened up a diff before.
thanks for everyones help?