MANY recent design improvements in hydraulic transmissions have followed the trend toward longer life of power-train components established by the use of a torque converter. The need for actual data relating to the characteristics of torque-converter operations led to the series of field tests reported in this paper. Off-highway trucks used in earthmoving, coal, and ore hauling were made available for the tests, together with experienced operators. Measurements of driveline stresses were recorded for trucks equipped with converter drives, and for those having mechanical transmissions.
Comparisons indicated that, with a converter, equipment can be operated at a higher load factor in order to get more work done, and also that the equipment will have a greater life factor. These two factors will result, of course, in reduced operating costs to the user.