Frequency analysis of a typical planar flexible multibody system with joint clearances

•The effect of joint stiffness on the frequencies of a flexible system is presented.•A slider-crank mechanism with flexible coupler and joint clearances is studied.•The floating frame of reference and assumed modes methods are exploited.•Fast Fourier Transform algorithm is used to find the frequency components.•Variation of the joint stiffness does not considerably change the frequencies.