- 1 - BRIEFING NOTE Withdrawal of AeroShell Grease 17 and replacement with AeroShell Grease 33MS Background AeroShell Grease 17 (ASG 17) comprises 95% AeroShell Grease 7 (ASG 7) with 5% molybdenum disulphide (MoS 2 ), a solid lubricant added to provide extreme pressure (EP) properties to the grease, for use in heavily loaded, sliding applications. ..