Grease Explained. I have shamelessly stolen this

[Bill B]

This popped up in my FB feed.  Pretty good explanation of grease and how it works.

Originally posted by the Branson Compact Tractors Group.



"Hey, you want to talk about grease? Yeah, let's talk about grease for a minute shall we? I get a lot of questions and also see them here about what grease to use and when and what for. Well, here is what I have learned the last 5 plus decades.

Grease has two main purposes. 1. To lubricate bearings and or metal on metal contact such as loader pins and bushings. 2. Grease drives away moisture and it also prevents new moisture from entering the element you are greasing. Basically grease is suspended oil mixed in with a main additive which is soap, or carrier if you will, to make it tackier. As the grease starts to liquify with use, the oil is released and the lubrication begins or rather continues. Several additives are placed in the grease such as those used in engine oils and hydraulic fluids. Those additives can be oxidation inhibitors, corrosion inhibitors, anti foam agents, rust inhibitors and anti wear compounds. Other types of grease carry extra additives such as Molybdenum Disulfide (Moly in common terms) and also graphite as well. Now there is a falsehood that runs rampant sometimes such as (You SHOULD NOT use moly on wheel bearings) Well, that simply is not altogether true. There are a few greases out there that do indeed contain 3% to 5% Moly and are 100% certified and approved by the NLGI (National Lubricating Grease Institute) and approved for both GC-LB which means GC is for high temperature wheel bearing service and LB is for chassis lube service. One of the very few that I am aware of is Mystik JT-6 with 3% Moly. It shows the certification right there on the grease tube itself. There are others, but I will not waste any more of your time on that. It is true however not to use grease with moly or graphite on wheel bearings that is not approved by being certified with GC-LB label.   

The NLGI administers standards for grading greases. In one such test, the hardness or softness of grease is rated by dropping a cone into a grease sample. The depth of penetration in five seconds is then measured and converted to one of nine NLGI grades from 000 to 6. (We use #2) The higher the grade number, the harder and stiffer the grease. Lower-grade numbers signify softer, more fluid grease. Another NLGI test determines the grease's dropping point, or the temperature at which a grease passes from a semisolid to a liquid. This dropping point, which can vary between 200°and 500°F. To measure the dropping point, technicians apply grease to the wall of a test cup and place it in a special oven along with a thermometer that measures the temperature in the cup without touching the grease or the sides of the cup. The dropping point is the temperature at which one drop of oil falls from the cup wall.
 
Now, you may ask why do so many grease types and brands come in so many different colors and flavors? Well that subject is kinda sorta erratic in the answers. For instance, Red colored grease usually means it is a NLGI #2 High temperature EP or Extreme Pressure grease that is approved for disk brake wheel bearings. Hold on a second, what? Not all red greases are the same. Most are, but there are certain brands out there that put the bling bling in their grease to make it look more pleasing to the eye. It is important to match the certification standard to the purpose you are using the grease for. ANYwho, Green normally is colored for marine environment use, blue can actually be an EP #2 or a general purpose use as well but not all blue greases are certified for high temps. Then you have the ole plain colored amber general purpose grease as well as clear, orange and so on. Now, the most important part you have been waiting for.

Which grease do I use for my tractor? Well, I am glad you asked. It all comes down to this. Grease those loader pins/bushings and grease them often. I will say it again for those in the back, GREASE those loader pins/bushings and grease them often. Now the general consensus for loaders alone, the best grease is one that contains 3% to 5% molybdenum (moly). Grease that contains moly is far superior at preventing wear on metal to metal contact. There is no question on this. Is red grease okay? You are absolutely correct. Actually any grease is fine except bacon grease (it's a joke ya'll come on with it) to lube your tractor. There are no high speed, high temp bearings on your tractor. It just needs some love and lube and often. What you use, is up to you. You favorite brand and color is all up to you as long as you use a consistency of NLGI # 2 grease. That is all, have a great evening."