Abstract: The present invention is directed to a crankcase lubricating oil composition for protection of silver bearings in locomotive diesel engines comprising (A) a major amount of an oil of lubricating viscosity, and (B) a silver wear protection additive composition, and (C) one or more detergents. The silver wear protection additive composition of the present invention comprises a mixture of (i) a hydrocarbylamine salt of a di-alkyl di-thiophosphoric acid and (ii) a hydrocarbylamine salt of an alkyl acid phosphate.

Abstract: A process for preparing an oligomeric phenolic detergent composition comprising contacting an oil soluble alkylphenol with an alkaline earth metal base, an alpha amino acid, and a C1 to C6 aldehyde, in the in the presence of a C2 to C6 alkylene glycol and a C2 to C4 carboxylic acid; and reacting under reactive conditions at a temperature of from 150° C. to 225° C. The oligomeric phenolic detergent product can be employed in a lubricating oil.