The Ford Barn

rotorwrench · 06-05-2020, 10:28 AM

We use a half dozen greases for the older helicopters. Each one has its use depending on bearing design and other factors related to load and temperature. Daily greases are similar to regular chassis type grease in that they are subject to break down relatively quickly due to loss, moisture, and dust or dirt debris. These greases have to be injected by hourly or daily use. They aren't designed to last long term. Sealed bearing grease is similar in characteristics but was changed over to synthetics for longevity. We still repack the major sealed bearings every two years with a bearing on the shelf life of four years. These lose their oil and the soap hardens over time. The spline grease we use is designed for very extreme conditions and also functions as a damper in cavities to keep shafts on center. There is only one company in the world that makes the stuff since it had lead in it as an EP additive.

I question the lab testing methods. Some of the tests have no bearing on lubricity of a grease. If you take a grinder to a bearing roller, no grease in the word is going to stop that kind of wear. I would call that an all or nothing test but the results really can be worthless for what the grease is designed to do and how the roller is supposed to perform. Folks that say a specific grease has never let them down likely have never tried any other type. In this day and age of cheap off shore copies of tapered roller bearings and the like, we are lucky if we have no failures. I have and it was never the fault of the lubricant used.

06-05-2020, 10:28 AM	#21
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,431	Re: Wheel bearing grease We use a half dozen greases for the older helicopters. Each one has its use depending on bearing design and other factors related to load and temperature. Daily greases are similar to regular chassis type grease in that they are subject to break down relatively quickly due to loss, moisture, and dust or dirt debris. These greases have to be injected by hourly or daily use. They aren't designed to last long term. Sealed bearing grease is similar in characteristics but was changed over to synthetics for longevity. We still repack the major sealed bearings every two years with a bearing on the shelf life of four years. These lose their oil and the soap hardens over time. The spline grease we use is designed for very extreme conditions and also functions as a damper in cavities to keep shafts on center. There is only one company in the world that makes the stuff since it had lead in it as an EP additive. I question the lab testing methods. Some of the tests have no bearing on lubricity of a grease. If you take a grinder to a bearing roller, no grease in the word is going to stop that kind of wear. I would call that an all or nothing test but the results really can be worthless for what the grease is designed to do and how the roller is supposed to perform. Folks that say a specific grease has never let them down likely have never tried any other type. In this day and age of cheap off shore copies of tapered roller bearings and the like, we are lucky if we have no failures. I have and it was never the fault of the lubricant used.