The characteristics of two misaligned journal bearings were experimentally studied. A bearing test rig was developed. The experimental journal was freely alignable in two possibly misaligned journal bearings. In Part 1, the static characteristics, such as the distributions of oil film thickness and the pressure and temperature of two misaligned bearings, are measured; the relationships of eccentricity, attitude angle, and side flow to the Sommetfeld number are experimentally determined. In Part 2, the traditional harmonic excitation method is extended to estimate the sixteen dynamic force coefficients of two misaligned journal bearings. Sixteen force coefficients of two circular journal bearings, each with two axial grooves, are estimated and the threshold stable speeds are predicted. Various experimental errors and the uncertainty of the estimated coefficients are analyzed. © 1996 by ASME.