To get you started, here is an easy read on grease basics.
http://machinerylubrication.com/Read/1352/grease-basics
What I have selected for lubrication for the steering knuckles of our M38 Jeep is -
Lucas Oil X-TRA Heavy Duty Grease about $4/14.5 oz tube
Lucas Oil Products Inc. Makes some interesting claims for this product. One of the most recognizable is that it is formulated to NLGI grade 2 (essentially the consistency of soft peanut butter.) They promote this product in this way - "Lucas X-TRA Heavy Duty Grease is a high quality polyuria grease excelling high temperature applications. It meets or exceeds OEM "Lube for Life" requirements and should last two to four times longer than conventional grease... is specifically designed to: Resist slinging out of fast moving parts, Resist washing out of steering components on wet roads, Resist melting a high temperatures up to 560 degrees Fahrenheit (dropping point), Resist "squeezing out" under heavy loads (Shear stability- One measure of a lubricant’s protective value is its ability to withstand shearing under pressure. Shear stability describes a lubricant’s ability to resist a decrease in viscosity due to exposure to mechanical loads), Maintain a constant film of protection even under irregular maintenance schedules, Good in cold weather; Exceeds performance requirements of John Deere, Deutz, Case-IH, New Holland and Massy Ferguson.
Specs -
http://www.bylucasoil.com/spec/x-tra-heavy-duty-grease
https://lucasoil.com/pdf/TDS_XtraHDGrease.pdf
How does this product do with soft or "yellow" metals? Because there are two bronze bushings present I wanted an answer on that - (TM refers to them as bearings in that they support and guide the axle shafts at either end of the axle universal joint). ASTM International proscribes a copper strip corrosion test (D-4048) with results categorized from the production of
slight tarnish, to
moderate tarnish, to
dark tarnish, to actual
corrosion. This is relevant because copper is a predominant alloy in bronze and brass. This product tested at level 1B meaning it would produce a slight tarnish. The 1B result is the final and highest level in
slight tarnish category, the next category being
moderate tarnish. My chemist said this should be perfectly suitable in this regard.
Because it doesn't use soaps as thickeners, such as in traditional greases, this extends the useful life of the product.
You will find the term "cone penetration" coming up again and again in the discussions of grease. This has nothing to do with tapered roller bearing or "cone-type" bearings. "The cone penetration method employs a weighted cone that is dropped into a fixed-size volume of grease for a defined time period. The depth that the cone is able to penetrate the grease is used to rate the grease’s consistency with a scale developed by the National Lubricating Grease Institute (NLGI)."
For an interesting read on this, see -
http://www.machinerylubrication.com/Rea ... onsistency
Finally, as with almost all polyurea greases, Lucas Oil X-TRA Heavy Duty Grease didn't do well in the category of getting thicker with the application of heat or stress. It is just really not how polyurea greases work. That said, it remains stable up to its drop (melting) point and stability is, perhaps, a better option.
So, I'm finally satisfied and now know more about grease than I ever wanted to know. If you are using something different and you are satisfied with the results, then you have also made the right choice.
Cheers,
TJ