My little LS180 quit pulling yesterday, never done that before. I checked the hydraulic fluid and it's not on the stick, I added 7 gallons I think. I ran it for about 10 minutes idling on concrete no fluid is hitting the ground. Checked the fluid and it's down about 1/4" on the stick from where I filled it. I used it for 5 minutes checked it again and it's off the stick. It's not in the crankcase, it's not in the gearbox on the motor and it's not in the belly pan. Doing some searching this morning it seems the most likely is it's in one of the chain drive boxes from a blown out drive motor. I will pull the plugs tonight and see if I can find it but does that sound likely?
By the symptoms you describe a failed shaft seal on a drive motor is the likely culprit. However the failed shaft seal might be a symptom of something else such as wear in the motor allowing internal pressure to pop the seal. Make sure you have a big drain tray available before you remove the plug...!!
Yep it's all in the left chain drive compartment. I'm not sure I have the time to fix it though =/