All of my searching on here tells me that on my 94 s10 4x4 4.3l engine W 3 button blazer the bottom 27mm bolt on the back of the transfer case is for draining the transfer case and the identicle bolt right above it is for filling it correct? Well I took the upper bolt out and alot of fluid came running out making me think for some reason you fill it through the sensor that is located up by the rear drive shaft. When I did pull my drive shaft a little fluid did come out making me think this but would someone please confirm that the fill line is the second hex bolt right above the drain bolt on my vehicle please.

 

You are correct...the identical hex bolt (I believe it is 10mm) is for filling. You fill until oil comes out of the hole. In other words...full is when the oil is at the bottom of the hole. The reason you probably had fluid coming out is because you have a seal that is bad an your transmission fluid went into your transfer case. Very common and there are a ton of threads about this.

 

Here are couple links that were shared with me by someone on this forum and I have been passing along as I found them very helpful. The third paragraph on the first link will tell you what has probably happened.

GMC Sonoma & Chevy S-10 Transfer Case Vacuum Switch

GMC Sonoma & Chevy S-10 Transfer Case Vacuum Switch

 

Well that's bad news if my transfer case seal is bad. I'm getting sick of this truck. I guess I am hoping that my bad transfer case motor that I replaced was the problem or maybe a stuck transfer case switch is the problem. I guess I will drain my t-case and fill the tranny and see what I get. I really do not wan't to freaking deal with this chevy POS anymore! at a 150,000 miles you would think you wouldn't have to replace everything on a truck but sure as poop if you own a chevy you better open your wallet.

 

just make sure you fill the transfercase and transmission separately as they are separate units. i had that seal go bad too. i noticed my trans fluid was going down but not leaking and sure enough the transfercase was way overfilled.

s10s can be a pain in the butt sometimes, but trusst me a older dodge or ford really aint any better, its just the joy of owning older junk. that seal is only like 5 bucks but of course dropping the transfercase isnt always that fun

 

Was the fluid hot when you drained it? I've noticed the transfer case oil expands quite a bit and mine seemed overfull when checking it the day after filling it. You can sort of check the seal by sucking on the breather hose and see if it holds vacuum.