Help, My son left our 1997 K2500 Suburban in 4-HI the other night, and then my wife drove it about 30 miles on the interstate (65mph) while it was still in 4. She called me because she said that she smelled something, and that the truck was acting funny when she tried to turn in the parcking lot. When I got there, I found that the truck was in 4-HI and there was some fluid leaking from the transfer case. I put it back in 2-HI and drove it home with no problems. My question is, what damage may have been caused by driving it this way, and what should I do to minimize the impact? Does the transfer case vent if it gets too hot? Should I simply replace the fluid, see if it still leaks, and if not, call it good?