There is a difficult problem to provide a reliable, faultless work of the bearing in the forward support of the low-pressure turbine (so-called "an inter-stage bearing"). After a few cases when D-30KP/KU engines failed as a result of improper functioning of the inter-stage bearing, it was decided to prepare a set of preventive measures. Doing this job, MMPO Salyut found out that its is possible to check the inter-stage bearing for defects by the noise it makes. Findings of this study allowed to prepare a new method on early diagnostics of the inter-stage beatings in two-shaft turbine machines. Measuring the noise allows to detect the bearing's sliding movement on the inner ring, roller fence and latitudinal lines a few hours before malfunction occurs. A noise-measuring device proposed by MMPO Salyut features such a high sensitivity that a 5-mkm declination in the rollers can be detected.