b which can be seen in fig7 the chocks are retractable and become positioned behind the flange 51 in order to ensure the immobilization of the support on the flange 51 the device serves as a support for three thermocouples 340 distributed equidistant from each other fig9 is a partial cross sectional view of the heating device 300 at the level of one of the thermocouples 340 the latter is bearing against the downstream surface of the journal in order to sense the temperature a cable 341 connects the sensor to the control unit which in particular comprises the function of controlling the heaters according to the temperature to be reached in this example it is seen that the thermocouple is attached to the wall 318 by means of a bracket 342 the device also supports three instruments 350 for measuring the distance between the journal 111 and the lp shaft inside the latter they are distributed equidistant from each other for example at three o 39 clock six o 39 clock and nine o 39 clock as seen from the rear of the engine the alignment of the lp shaft is carried out by comparing the differences in measurements of distances at these three points and by correlatively acting on the transverse positioning of the shaft in.