Originally Posted by Ketcham
Of those who have done this job themselves, is it pretty involved or similar to changing oil and transmission fluid. Open the drain, and refill?
Changing the transmission fluid at least on the 6.0l diesel is much more difficult than changing the engine oil, but maybe you don't have a diesel. In any case you might search a bit more, I know there are a lot of post regarding this.
You would be wise to follow the maintenance schedule as that first change to get the metal filings out is important.
Personally I found changing the Atlas T case pretty painless, with the right preparation. Changing the fluid in my front Proroc 60 was a bitch - mainly getting the front cover off with out causing damage to the mating surface.
Here are my notes that I compiled - hope they help and your fluids may differ:
CHANGING FLUID IN ATLAS TRANSFER CASE
Change Interval: every 20,000 miles
Lubricant: 2 qts Amsoil 75-90 Manual Transmission & Transaxle Gear Lube GL4 (Product MTGQT) It is honey colored and in clear plastic bottle Front Differential is 75-90 but Severe Gear and in black plastic bottle dont get them mixed up
Talked to Atlas about proper way to fill T-Case:
Easiest method would be to drain fluid out bottom opening drain plug (7/8 socket ½ drive) take note of drain plug it has small rubber gasket inside washer dont disturb - lube drains out pretty easily into 5 gal. bucket
Take off upper end of fill tube at the rear of the T-Case - you will need to disconnect speedo wire and make sure to re-attach it when done some oil will drain out this tube
To remove top sight tube connection, you will need 11/16 & 5/8 open end wrench
Fill Oil Safe container up with 2 qt. lube and route inlet over top of T-case, you will need a helper to do the pumping while you hold inlet tube in place pretty easy to pump, works well
Will need Teflon tape to re-tighten fitting, dont over tighten as you are dealing with aluminum fittings should see level rise up to old mark on sight tube
Remember to reattach Speedo wire
CHANGING FLUID ON DYNATRAC PROROC 60 FRONT DIFFERENTIAL
Have 13 bolts to take off, use 5/16 12 point Ό drive
Use Gasket Scrapper tool but will need several new razor blades
Have to remove cover plate sucking will not work and you could damage ARB locker as it has a copper air line that runs right by the fill hole
Use big chisel and big hammer (try ball peen hammer but ended up using small sledge hammer) - try not to damage plate
I used Permatex Blue RTV (it lists uses as differential covers) but Red silicone was originally on cover, and Black RTV also listed for differential
Be careful not to gouge mating surfaces, and if by pounding cover off, you have gouges, use Emery cloth sandpaper with steel block to sand smooth & level
ARB manual says clean or replace vent tube
Clean all mating surfaces with denatured alcohol
Dont over tighten fastners
I only put RTV Blue on one side, and moderately tighten, then come back in 1 hour to fully tighten cover as called out on Permatex instructions
Fill with 2 Qt. Amsoil Syn 75W90 Gear Lube Severe Gear in the black bottle (Product Code SVGQT)
ARB maintenance manual said to fill near top of fill hole, then manually rotate front drive shaft and see if it needs any more
Called Dynatrac he said they put in 85W-140 non-synthetic, but said lots of folks use Amsoil
Also note that Ford Tech put longer vent tube in