NP 205 gear oil question

[kxnomore]

I went to drain the transfer case today and auto trans fluid came out.

How much damage has been done? It was a bit clanky (is that a word?) but seemed to be working fine. I've put at least 200 miles on it since I bought the truck and never thought to change it...

Should I just fill it with gear oil and hope for the best?

[kwmech]

It wont hurt the t-case, but you have a problem with the seal between the trans and the case

[DESTRO]

Sounds to me the PO filled it up wrong.Just fill it up with the right stuff and keep an eye on the tranny fluid in the transmission.As long as it isn't disappearing you should be fine.
I would probably fill it up with some cheap wal-mart oil and then drain it right away just to help flush all the trans fluid out first. Then put your good stuff in.Not needed but that's just me.

[Blazer1970]

That won't hurt a thing. In fact, GM spec'd ATF for the later model 205s that were used behind automatic trannies. It is very hard to keep the tranny from leaking ATF through the adapter into the t-case.