The performance of solid lubricated ball bearings was examined under a high thrust load, up to 3 kN, in a vacuum. Tested bearings were (1) angular contact ball bearings with a sputtered molybdenum disulfide (MoS2) film on balls and races, and with a PTFE based composite cage, and (2) angular contact full complement type ball bearings with an electro-plated lead(Pb) film on balls and races. Low ... [Show full abstract] frictional torque of about 1.5 N cm at a load of 3 kN, and a long life of 3 x 10(exp 7) revolutions were obtained with the bearings with a sputtered MoS2 film. However, torque spikes with a duration of about ten seconds and with an interval of several hundred hours were observed. The peak value was as high as 30 times of that in well lubricated state. An electro-plated Pb film also successfully lubricated a bearing for over 6 x 10(exp 6) revolutions under a load of 3 kN, although the frictional torque was about 10 times higher than that obtained with the MoS2 lubricated bearings.