Variable axial land geometry dampers can significantly alter the unbalance response, and in particular, the likelihood of undesirable jump behavior, of circular orbit-type squeeze film dampers. Assuming end feed, the pressure distribution, the fluid film forces, and the stiffness and damping coefficients are obtained for such variable axial land geometry dampers, as well as the jump-up propensity for vertical squeeze film damped rigid rotors. It is shown that variable land geometry dampers can reduce the variation of stiffness and damping coefficients, thereby reducing the degree of damper force non-linearity, and presumably reducing the likelihood of undesirable bistable operation. However, it is also found that regardless of unbalance and regardless of the depth, width or shape of the profile, parallel land dampers are least likely to experience jump-up to undesirable operation modes. These conflicting conclusions may be accounted for by the reduction in damping. They will need to be qualified for practical dampers which normally have oil hole feed rather than end feed.Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in San Diego, California, October 19–21, 1992