A viscous seal for fluid transfer devices that deviates from the conventional wisdom of avoiding contact between the seal and a rotating drive shaft of the fluid transfer device. Instead of avoiding contact, contact between the seal and drive shaft is used to effect axial alignment of a sealing sleeve with the shaft. As a result, the viscous seal is compliant in that the sealing sleeve can follow the axis of the drive shaft. Accordingly, the sealing sleeve can fit snugly around the drive shaft for more effective prevention of leakage of low or any viscosity fluid along the drive shaft, but without any significant radial load being applied to the sealing sleeve that might cause undue wear or damage due to galling.