1998 rodeo 4x4

I HAVE A 1998 RODEO WITH 17000 MILES ON IT. THE PROBLEM IS THAT MY FRONT WHEEL 4X4 HIGH GEAR WONT ENGAGE. BUT THE LOWER 4X4 GEAR WILL? THE FRONT SEAL OF THE DRIVE SHIFT LEAK OUT BLACK OIL? THE TOW TRUCK DRIVER SAID THAT THE TRANSFER CASE IS BAD? IS THIS TRUE?:shakehead

:) Is it an auto or manual? First Id change the transfer case oil and front differntal lube, and look at it very carefully to see if any metal is in there. Andie:)

Do you have 17k miles or 170k miles?

If you have 170k miles, when was your last transfer case fluid change?