Do I put gear oil or transmission fluid in my transfer case for my 1991 Z71?

The truck has set up for a couple of years and I need to change it. Also, where can I get a pump to suck out my gear oil in my differentials and it's a very tight spot to try and pour the fluid in via a funnel, so how do I fill my differentials back up with gear oil?Do I put gear oil or transmission fluid in my transfer case for my 1991 Z71?
The transfer case takes ATF. I just serviced mine and it's a 1995.





You can get a pump for the differentials and the transfer case at Auto Zone. Although I advise that you take the differential covers off and clean the insides out with a clean rag. I suggest Royal Purple as it's the best thing on the market that I've been able to find so far.Do I put gear oil or transmission fluid in my transfer case for my 1991 Z71?
Use gear oil. On the pump to pump it out you may find a unit that is driven by an electric drill at your local auto parts store.





I found a pump at Wal-Mart in the automotive section next to the quart bottles of the gear oil. It has the pump and a clear hose that you can put into the opening and press the pump to fill the axle. But I forewarn you that it will take a while to pump the oil into the axle or transfer case.
Not sure on the transfer case oil, but I thinks it uses ATF.





The best way to change the differential oil is to remove the cover. That will get all of the old oil out and you can take a rag and wipe out any metal filings that might have settled at the bottom, and trust me there is some metal down there. Just get a tube of RTV silicone sealant to use for a gasket (I have never used a gasket for the gear cover and never had a leak). To make it easier to refill, simply cut a piece of rubber hose and slip it on the nipple of the bottle the the gear oil comes in. EDIT: In reference to your question about the oil if it's a positive traction unit or not.... It's not actually different oil, it is an additive for the regular gear oil.
Depends on what transfer case you have . in 91 , most of them do use AFT , but to be safe , open drain plug and look at what comes out . It is very easy to tell the difference . Most Parts stores carry a suction gun for that job . It comes with a hose that will go inside the filler hole and then you suck it out . Reverse procedure to put new in .
buy a pump form parts store.....will fit onto the bottel of gear oil and pump it in...also can buy another pump or use same 1 to pump out old fluid but pulling the drain plug shud get most of it.....as for wat fluid i believe its gear oil...repair manual will tell u exactly.....and if its posi u have to add posi lube....good luck
Gear oil and if it is a posi it requires a fluid specifically for a posi gears.