Operation of production vehicles in conditions of negative temperatures is related to certain difficulties. One of the main problems is the intensive heat extraction from the unit surface in the environment. As a result of heat exchange, the thermal mode of the unit work is broken. It leads to the change of viscosity-temperature characteristics of lubricating oil. Operation of transmission units in such conditions results in the decrease of vehicle fuel efficiency, diminution of service life of the main units and parts and deterioration of ecological efficiency of their work. This article is devoted to the experiment of using thermal insulating materials aimed at reducing heat loss in the transmission. The method of calculation of thickness of a thermal insulation layer is proposed. The necessity of the employment of infrared thermal imaging to detect areas subject to insulation is substantiated. It is revealed that the area of insulation on the unit under study makes up 1.45 m2. The intensity of transmission cooling with the use of liquid insulation is studied. It is established that the insulation of the unit casing allows reducing heat removal rate and increasing cooling-off time from 360 to 540 minutes. The process of heating of the thermally insulated unit is studied. It is determined that the use of liquid insulation allows intensifying the unit heating. The time to stabilization mode decreases by 35% to 45 minutes, and the stabilized temperature increases by 8 K.

Several ways of technical diagnostics have been researched. General aspects have been considered of the mechanism diagnostics by vibroacoustic signals. The assessment of the vibroacoustic engine diagnostics method is provided. On the basis of a laptop computer, a portable diagnostic complex has been elaborated for the pre-assessment of combustion engine mechanisms' condition using parameters of a vibroacoustic signal. For technical assessment of combustion engines a diagnostic scheme has been proposed for mechanical components by vibration parameters.

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