A gerotor and methods for assembling the gerotor are disclosed. The gerotor includes a pump housing having a channel and a rotor positioning cavity, a pump shaft, an inner rotor, and an outer rotor. The pump shaft has central pump shaft axis and the inner rotor has a central inner rotor axis. The methods include: inserting the pump shaft through the channel; sliding the inner rotor onto the pump shaft at an oblique angle such that the central inner rotor axis is at least partially angularly offset from the central pump shaft axis; rotating the inner rotor to substantially align the central inner rotor axis and the central pump shaft axis and to engage the pump shaft with the inner rotor; and positioning the outer rotor around the inner rotor to maintain substantial alignment of the inner rotor with the pump housing and/or the pump shaft.