[Superduper]

Originally Posted by daTeacha

I don't pretend to understand how the sludge got there, it's just what the guy said he found in an older and non-maintained machine.

If the system is ventilated and has a breather, perhaps it's not so far fetched. Air always contains moisture to some extent. At a certain temperature, that vapor will return to a liquid form. Google condensation and dew point and you'll get some good information. Unless your tractor is constantly stored in heated garage, cooler morning temperatures could cause the water vapor to return to fluid state and contaminate the oil. Water + oil turns to sludge, right? In the mornings, even on some summer mornings, my tractor has dew on all the metal parts when I go out to greet it. If this happened on the inside of the crankcase and tranny case, it might build up over time, especially if the tractor is not brought up to operating temperature. Just a thought.