Transfer case fluid
I have a 2000 k2500 (old body style) crew cab 4wd with what I suspect to be a 4L80e auto and a definitely a 350 engine.
I ran the truck in 4HI on pavement for alot longer then I should have. I forgot to take it out of 4h. (completely embarassing) I have the stupid electronic 4wd selector for 4L 4H 2HL and N mounted on the dash (blocked by the tranny shifter). Needless to say I don't think I did much damage other then wear on my tires. But I think I should change the transfer case fluid (which is the drivetrain componet that I think took all the abuse).
My question is this: The manual says that automatic transfer case take ATF and conventional (old school) cases take 80w90 gear oil. What do I use? The truck does not have any kind of auto fourwheel drive system (like I think some of the suburbans do).
I tried the BBS archives but could not find anything that addressed this issue.