Igloo
Regarding your request for D2 Lube points, there are many.The D2 Operation and mantnance instruction book list Lubrication instructions on page 6 all the way through page 21. It is a handy book with more than just basic owners manual info. They are listed for sale here and on E bay from time to time, also available from Cat legendary literature for big $
Regarding your frozen steering clutch, you are right its is time to Drain. But do not replace they should be dry clutches. There is a 3/4 inch pipe plug, one under each steering clutch you should remove to drain water and whatever. Some guys drill a small hole in the drain plug and put in a cotterpin to rattle around to keep it open.The Cat manual mentions washing the stearing clutch compartment with kerosene.
I believe someone here has the D2 manual posted on there website
D2 Specifications U series