Hey guys:

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.

Any ideas?

Well my 96 with BW4401 floor shifted t-case takes ATF...

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if im not mastaking np205s where the only ones that took gear oil, all the chain driven t cases take ATF.

i'd go with ATF

I looked it up at work for you and it definately takes ATF not gear oil. Hope this helps you out!! [img]images/graemlins/40BEER.gif[/img]