| abstract |
Lubricants and additive packages that give exceptional performance as heavy duty gear lubricants are described. Four essential oil-soluble additive components are used in combination, viz., a metal-free sulfur-containing antiwear and/or extreme pressure agent having a copper corrosion test activity of not more than 65; a metal-free phosphorus- and nitrogen-containing antiwear and/or extreme pressure agent; an organic carboxylic acid; and an organic amine. Tests comparing the performance of the invention against a commercial premium API GL-5 gear oil additive package selected as the best available package by a well-known OEM have shown the superiority of the present compositions under a number of test conditions. |