While waiting for the engine during its passage through the machine shop, I had taken a closer look at the clutch housing.  It had sat exposed to the elements for many years and had standing water and lots of crud in the bottom.  The water had obviously created a lot of rust, which I attacked with wire brush, putty knife and chisel.  The hydraulic lines were what most concerned me.  The return line was full of greasy looking gunk.  The pressure line looked like it had been filled by mud daubers, wasp-like insects that build mud nests and will fill any small opening or tube to suit their needs.  I realized I was going to have to split the tractor behind the transmission, too, another aspect of this project I had not originally anticipated.

I had already opened the drains on the hydraulic reservoir section and differential draining a lot of water from the hydraulic section and thick goop from the differential, but I was not prepared for what poured out once the transmission was freed from the rear section.  It was the nastiest looking petroleum goo I had seen yet and it didn’t smell any better than it looked.  I had a floor jack under that section, so I lowered it as far as it would go and let it drain into a pan, assisting the process with a can of brake cleaner.