ONCE EVERY DAY TRACTOR IS IN USE ----+----------------------+----------------------------+----------- U | Steering sector shaft| One complete turn | Cup Grease ----+----------------------+----------------------------+----------- D | MECHANICAL LUBRICATOR | Fill with a good grade of heavy gas engine cylinder oil. | Turn the crank on the mechanical oiler 40 to 50 times when | starting the engine. | IMPORTANT | In cool or cold weather the oil in lubricator tank must be | warmed as it will not flow readily unless of the right | temperature. ----+--------------------------------------------------------------- G | TRANSMISSION | In warm weather, use heavy oil such as “600” transmission | or Polarine transmission oil; in cold weather, use a good | light oil. S | GOVERNOR | Cylinder oil in governor should cover shoe. M | MAGNETO | Oil magneto bearings once a week with sewing machine or | cream separator oil. ----+--------------------------------------------------------------- The oil used in an engine is thicker, and has a high _burning point_ and high _viscosity_; that is, it should be able to resist burning, and should not get so thin when it is heated that it will be squeezed out of the bearings. The same kind of oil that is used in the engine can be used in many other parts of the tractor. Grease is usually used for the gears of the transmission and drive. There is very great pressure between the teeth of two meshing gears, and only thick oil and grease have sufficient viscosity to resist being squeezed out. The thickest grease is used on the tracks of caterpillar-type tractors. Before operating a tractor, the lubrication chart supplied by the manufacturer should be studied with great care, and all of its requirements should be observed. This chart is usually in the form of a diagram accompanied by a table, as shown in Figure 73, which is the lubrication chart of one of the International Harvester tractors. This figure illustrates the constant attention that is demanded by this most important part of tractor operation. [Illustration: FIG. 74.—“ILLINOIS” OILING DIAGRAM] The table calls for four lubricants, these being sewing machine oil, which is very thin and liquid; gas engine cylinder oil; transmission oil, which is as thick as molasses; and cup grease, which is like butter. The engine is oiled automatically, the only requirements being to keep the oil tank filled, and to be sure that the oiler is working. The other parts of the tractor are oiled or greased by hand. Figure 74 is the oiling chart of the Illinois tractor.