Use a high grade neutral mineral grease composed of a soda soap base and a clean refined mineral oil. types or specifications. Do not mix greases of different A satisfactory grease should have the follow- ing qualities: 1. Freedom from abrasive matter such as grit, tale, mica, clay, or fillers of any kind. 2. Freedom from corrosive substances such as free lime, iron oxide, etc. 3. Freedom from acid, alkali and moisture. 4. At operating temperatures, a consistency low enough to prevent excessive channeling yet high enough to avoid fluidity which would create churning or leakage. 5. The least possible tendency to change consistency such as hardening, thickening, or separation into oil and soapy matter. 6. A melting point considerably higher than the operating temperature. Use only clean lubricant from clean, closed containers and keep it from becoming contaminated during regreasing operations. lubricate. grease. Do not over- The nousing should be no more than about one-third full of Too much grease will cause churning, resulting in grease separation, overheating, and grease leakage. Add grease sparingly observing precautions as to overgreasing. Complete regreasing is best left until the time of overhaul. More complete renewal of the grease can, when necessary, be accomplished by forcing out the old grease with the new. Thoroughly 3-48