Another simple service your truck will thank you for if its been a while. If your wondering why this thread is here, read my "how To" differential change thread. Anyways, You should know again, that your transfer case fluid should be changed every 30,000 miles, or two years. The t case holds two (2) LTRS. My t case is a NP8, so depending on what your truck has, you might need to go the GM and buy there rip off "Auto-Trak 2" transfer case fluid . If you are not sure about what type you have, I would call up GM and ask. Or you can look up your vin number and figure it out, but I think there are like five or six different varients of t cases so make sure before you go buy plain transmittion fluid. The time frame for this project is going to be one (1) beer because it is very simple. If your like JK and you like to have a good time while you get your fluid change on, you can push it to six beers.
Things you will need....
1. Two ltrs of Auto Trak 2 fluid (depending on your vehicle)
2. A pump of some type (autozone has a nice 10$ one)
3. A drain pan
4. Shop rags
5. 19mm socket and a 3/8 drive ratchet
6. A beer of your choice
Helpful additions (not required)...
1. Floor creeper
2. Drip pan
Procedure:
1. Drive around a little to get the fluid warm. Remove fill bolt (above drain bolt obviously) with the 19mm socket.
2. Place drain pan a little away from the drain bolt, the fluid will have some momentum.
3. Remove drain bolt, let the fluid drip for a while. If you have the truck on jack stands or ramps, it helps a little because the hole is angled down.
4. Clean both bolts. There are not magnets on them like the differential's, but mine had thread sealer, so a wire brush or pick helps get that crap off. Clean the surface where the bolts sit and re-install the drain bolt.
5. Get your pump or whatever you are going to use to get the fluid in, and start filling. If your truck is on jack stands still, you might want to lower it off. It makes it harder, but you will be able to get more of the fluid in since the bolt will be level again. You want to fill the t case up till the fluid is at the rim.
6. Re install the fill bolt. If you are not useing new thread sealer and you took the old stuff off, you might need to tighten the bolts down a little harder. Not so they are as tight as they can be, mine still had a few threads left showing.
7. Drive around, check for leaks, and your set.
Hope this helped if you were planning on changing your t case fluid. Its a simple drain and fill job, but people still mess up (wrong fluid, not enough fluid, wrong tools...ext) You experienced guys have any tips, tricks, feedback, alternative methods, lets have them. Even you can do this cris!
