George,
If you would please supply a direct link or copy to these greases that state "for use on heavily loaded sliding surfaces only".
Interesting enough, Since I do respect your opinion, I felt I better do some checking before going further.
I called our head chief chemist/CLS,Larry Ludwig to get his prospective on this.
In short, he states "that is not correct. He feels your client might have had problems with those u joints due to poor lubrication pratices, not cleaning the gun or fitting prior to greasing each fitting, had blown seals and so forth."
Moly is harder than the bearing and race surfaces of non-friction bearings. As the bearing rolls, the moly is roled over by the softer bearing surface, causing the bearing surface roughness, erosion
This is incorrect. The interesting thing about moly is that not many oil companies have look at using moly in the automotive industry (including mobil) until recently. There is a lot of mis understanding on just how moly actually works and how it affects the asperities on metal surfaces. Moly does not erode a surface but in reality fills in the surfaces, and this provides a smoother plain. Kinda like heat sink compound is on the computer proc your using. Metal surfaces do not look jagged but under a scope, the smooth metal surface actually has asperities or peaks and valleys.
You might want to look at this as I try to explain to the best of my knowledge about moly.
http://www.bobistheoilguy.com/moly1.html
I think this should give you a better general understanding on moly as I know of it.
Also,Since it was at a coal mine, coal dust would have been introduced on top of the fact most likely they were using a lithium complex grease that would absorb water into the mix.
Coal dust will cause erosion and wear as it is like some graphites and can polish the metal surfaces.
Another point that many fail to understand is that moly will wear off. It is not permanent but sacrifial and will go away. Given this, If a company or employee fails to lubricate with a lithium based grease, because lithium if exposed to standard moisture rain and such, that it being a soap, will emulsify, and wash out, therfore so will the suspended moly, leaving what ever moly is plated for a short time before being completly worn away, thereby losing any lubrication it had on it.
BTW, I have a big asphalt plant down here that has been using our 238 #2 grease for over 2 1/2+yrs now and it has not seen a bearing failure. The interesting part of this is that they started out using 6cases of-30 tube grease every 2 months. second 2 months same, 3d 2 months they were sitting there with 2 cases not even opened yet. They now only oder once a year as their plant doesnt' use near as much grease and they don't waste near as much time having to grease as frequently. The asphault is also abrasive as well but if proper lubrication practices are in place with the right kind of complex for the enviroment, with a good moly barrier additive, it should not give you any problems. Needless to say, they have been approached by many especially ones with the hammer spatter test, and as of yet, they will not change due to the bottom line savings they have.
[ September 10, 2002, 06:11 PM: Message edited by: BOBISTHEOILGUY ]
