How to change F & R Differential fluids

[Hummerguy32]

Originally Posted by HUMMERICH23

So is it a good idea to do Transmission as well at same time if you?re doing Differentials and T-Case? I am in that position where with 38,000 miles i want to get Fluids switched out to Schaeffer's in my TC and Diffs but was considering doing tranny too. I know the Dealer wants 550 for Diffs, TC, Tranny, but I would only do it if they let me use the fluids i want like Schaeffer. I am wondering if i am better off doing TC/Diffs myself and having a tranny shop do the flush? Is it best to flush or should i just drain out like the 5 quarts and just replace?

Thank you again for all the suggestions. The diff's look like no problem w/ my work ethic in the construction industry so i can accomplish though i understand what some may think the dealership should do.

FYI: I did however have the dealership do the tranny flush. I do not have one of those flush machines to really suck all of it out of that area.