Just noticed a small wet spot under my car. The t-case is leaking, what's the common cause?

 

Big O ring in between the tcase and trans. What color fluid is it? Tcase holds 2 types of fluid, acd and case, ones red and other is basic oil color. Spray it off with brake clean and take it for a drive, lift it up and snap a pic for us

 

The normal leak I've seen is where the stubby shaft comes out of the transfer case. If the seal isn't flat or the metal dust cover on the connecting axle isn't perfectly round, you'll lose fluid.

 

Great, I'm getting the car on the road this week. As soon as I clean it up and drive it a bit, I'll snap a pic. Thanks for the info.

 

Update, it's red fluid, I'll post a picture tomorrow.

 

Well your acd system has a leak, where is it coming from? There is a line on top of the tcase thats bolted down by a banjo bolt, maybe the 2 crush washers are bad.