Gear oils specifications

Manufacturers and other bodies have issued their own designations, which may be encountered occasionally. Most important is the US Military specification MIL-L-2105D (which replaced M1L-L-2105C) corresponding to API GL-5, and introduced approval for multi-grade gear oils. 

To satisfy the specific needs of these applications, numerous detergent and dispersant substrates have been developed. The aim of this chapter is to highlight the synthesis and utility of the most industrially important of these. Emphasis will be given to engine lubricants since this application has the largest commercial demand for detergents and dispersants. But other key areas, such as gear oils, transmission fluids and fuels, are also considered. 

CPChem s Synfluid PAO 25 cSt, which is produced with the ionic liquid catalyst has a viscosity at 100 °C, which is unique to the industry. Prior to this product, a 25 cSt PAO was only available commercially by blending higher and lower viscosity PAOs. The specific applications for this product are typically gear oils, greases and various industrial lubricants. 

Broken machine castings, not conforming to specifications Hydraulic oils, gear oils... 

For industrial gears and circulating oils there is a specification published by the American Gear Manufacturers Association, which expresses the viscosities corresponding to the AGMA Lubricant Numbers in Saybolt Universal Seconds only. The approximate viscosities in centistokes are provided in Table 52.4 for convenience. The recommendations in Tables 52.5 and 52.6 are intended as a guide for lubricant selection. 

The API SM specification, set out in Table 17.9, has mainly similar aims to that of CJ-4. The differences are that the CJ-4 heavy duty diesel specification has a major pre-occupation with the effect of combustion soot-induced thickening of the oil arising from relatively recently introduced environmentally associated emission controls, whereas API SM uses the ASTM sequences IIIG and IIIGA to measure the ability of the lubricant formulation to withstand (mainly) oxidative thickening. Phosphorus and sulphur content limits of lubricant formulations are set. The major part of the API SM specification is concerned with in-cylinder component and valve gear wear. 

While no analytical methods were located that are specific for detecting Stoddard solvent in sediment, as with water and soil, methods that detect other hydrocarbon mixtures may be applicable. For example, quantification of fuel oil hydrocarbons from sediments is a relatively involved process. Following extraction, the saturated and olefinic hydrocarbon fraction is separated from the aromatic hydrocarbon fraction using thin-layer chromatography or column chromatography. Fractions are subsequently analyzed by GLC (Gearing et al. 1980). 

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