Design/methodology/approach An experimental study is presented to identify the lubrication deterioration under sliding-rolling contact. Sliding-rolling experiments with controlled loads, slip ratios and speeds are carried out on a roller-ring test rig. The deterioration of lubrication condition is analyzed by the transient oil film thickness and two perpendicular vibration signals, respectively. Findings The oil film thickness and the vibration signal play different roles in characterizing different lubrication deterioration conditions. Specifically, the degree of lubrication deterioration with slight solid-contact is indicated by the rapid reduction in oil film thickness. The degree of lubrication deterioration with severe solid-contact is reflected by two perpendicular (vertical and tangential) vibrations. Furthermore, the tangential vibration can indicate the occurrence of sliding in rolling contact. Originality/value A full characterization of the lubrication deterioration under sliding-rolling contact can be accomplished by integrating both the oil film thickness and two perpendicular vibration monitoring. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0244/