Leonessa Group

Maintenance of slewing rings

Controls on lubrication, bolt tightening, the state of the seals and machine backlash es must be carried out periodically.


Lubrication of the raceways is carried out at intervals depending on the conditions of use of the machine. We recommend that the raceway be greased after the first 50 hours of use, and then after every 100 hours of use. Before and after long periods of disuse of the machine, a new bearing lubrication should be carried out.
The operation of pumping the grease should be carried out while the bearing is rotating and should be considered complete when the grease leaks from the seal and forms a light film, which also creates a seal.
In the event that this visual inspection should prove impossible, our Technical Department can communicate the amount of grease to be used. The grease should be spread on the gears by using a brush or by spraying, and must completely cover the sides of the teeth. Where it is impossible to carry out a visual check for the presence of grease, we recommend that you carry out greasing every three or six months, according to the use of the machine. The table shown in the section on Assembly/Lubrication provides information on the greases to be used. For special applications that require grease at low temperatures, we invite you to contact our Technical Department.


After the first 100 working hours an inspection must be carried out of the tightening force of the bolts, according to the values indicated in the following table. After which we recommend that an inspection be carried out once a year. The frequency of the inspection can be reduced in the event of particular conditions of use. If, during the inspection, loose or worn bolts are found, they should be replaced.


The seals mounted on the La Leonessa slewing rings are made with a basic elastomer in nitrile rubber, which has good characteristics of resistance to temperatures and to weather conditions.

During the lifetime of the slewing ring we recommend that you carry out visual inspections on the state of the seals, and do not hesitate to replace them if they appear to have deteriorated or become fragile.


As described previously in the section on Assembly/Assessment of machine backlash, the first measurement recorded is the reference for further measurements that will be carried out and that represent the wear of the slewing ring raceways.

It is good practice to carry out measurement once a year. The maximum acceptable increase, before having to replace the slewing ring, depends on the diameter of the ring, on the type and size of the rolling elements (balls or rollers), on the type of application for which higher limits of wear can be accepted if this does not compromise the functioning. When backlash increases by four times the initial backlash, do not hesitate to contact our Technical Service for the evaluation of the state of wear on the slewing ring.


LA LEONESSA S.p.A. a socio unico
VL. Santa Maria, 90 - 25013 Carpenedolo Brescia - Tel. +39 0309965435 - Fax. +39 0309965629
P.IVA 02199340981 - Email