[R-390] Silicone Grease

[Dennis Deaton]

Hello to everyone on the list,

There's been a recent thread on the list concerning a silicone-grease-type lubricant for the R-390 gear trains.  I got a tube of some Dow Corning High Vacuum Grease from the local Dow distributor.  Can't remember the cost.  It's used primarily to seal rubber o-rings in food machinery.  I believe its the stuff that used to be marketed as DC-4.  I remember using DC-4 just about every where when I worked on AN/SPG-55B Radars at Sperry Gyroscope.  It came in handy when lubing the geartrain for the train and elevation servo indicators.  These gear units resembled the RF deck gear trains of the R-390A in complexity, so I think that the grease should work fine in that area.  When I tear into my first-contract Collins-built R-390A, I'll let you know the results.

Dennis Deaton, WA6ACC
Redlands, CA