After sitting all winter, Gear oil is about 2 inches low and leaking between the sprocket and the hydraulic motor. A vacuum pulled air in when I opened the fill port. My track links are frozen/stiff in many places, so the motors have to work really hard to turn them. What are the odds that the extra work/tension caused this, How safe is it to finish a project for a couple days while topping off the TO4 oil?
Check it in the morning and at lunch, unless it leaves a slug trail you should be fine. Look for any misalignment and obviously keep an ear out for odd noises. It's possible just sitting and some dirt are causing some leakage and running will "cure" it. I never get that lucky though. Giving it a good wash will help dislodge any hardened mud that may be affecting the seal. Soon as possible open it up and inspect bearings, etc., and replace what is probably a floating or as CAT sez, duocone seal.