carrothead,

  I am not sure what the oil Ihave is. It is at least 40W or heavier, as I think the clearances in the Madison Kipp oiler are probably not all that tight. Plus it is used to oil the final drives before going on the ground (I hope EPA doesn't find this out!) I have Caterpillar machinery here on the farm and they have an oil annalysis lab I might send some to, to see what they can tell me. Unless of course a genuine Hart Parr fan here can tell me what it requires. Uncle told me but I did not write it down, and he is no longer with us to ask. 

Don't worry about the tractor getting out of family hands.....It won't as long as I am alive!!! My daughters love it too, and both want to ride it when ever we get it out. The only thing it needs is a steering box rebuild, as it is quite loose. Oh, and the trans seal, at the base is leaking. Looks like a major repair to fix it though, as the cross drive shaft between the wheels has to be removed, to raise the transmisssion, to replace the gasket.

I guess that about all I know, I wish there were more posters here with information. From what I see it is pretty slow around here. Thanks for asking, Kirk