There is a pump inside the transfer case and it eventually wears a pinhole in the casing and the fluid will only leak while it is under pressure. So there won't be any puddles under your truck. There is a aftermarket spacer that can be installed and it is a harder metal than the case so it won't wear. I'm still not sure why the factory doesn't install the spacer. It cost me $1200 to get my t-case rebuilt, but I pulled it and took it in. Hopefully you caught yours in time and may not be so expensive.