S15 Sonoma, transfer case drain plug?

[otis24]

Can anyone please point me to the location of the transfer case drain plug on my 1994 GMC Sonoma? I found the fill plug, but did not see a drain plug. Also, I assume it takes regular gear oil (80-90). How much gear oil does it take to fill the transfer case? Any help is greatly appreciated.

[Gmcsuvguy]

There are 2 18mm plugs on the back of the transfer case, the top one is the fill/level plug and the bottom is the drain, and I believe it holds about 1 1/2L of atf.

[Pete95Sierra]

to drain it you have to take the cover off... than seal the cover with permatex blue or black.....then fill the diff it until it overflows out the fill plug with your recommended gear oil

[otis24]

Looking at my owners manual, it shows a transfer case fill plug and drain plug. It also shows a front axle fill plug. Are these two different things? How do you drain the front axel? Does one take gear oil and one take tranny fluid? Now, I'm really confused!

[otis24]

OK, I found the transfer case and located the drain and fill plugs. How do I drain the front axel? Is it necessary to drain the front axel, of do I just keep topping it off as needed? I would prefer to drain it, so that I may add Auto-Rx. Same with the transfer case. Any help would be appreciated.

[Gmcsuvguy]

The front differential only has a fill plug. To fully drain it you actually have to remove it and tip it over. I have heard of guys drilling a hole and tapping it to fit a drain plug.