A vehicle includes an integrated drive module coupled to an axle thereof. The module includes a hydraulic motor configured to provide motive power at an output shaft, and a differential for distributing the motive power to right and left portions of the axle. The hydraulic motor and the differential are encased within a common housing. The vehicle may include a second integrated drive module having, within a housing, a second hydraulic motor (or multiple hydraulic motors), and a second differential coupled thereto and configured to distribute motive power to right and left portions of a second axle. The second module may also include a transmission within the same housing. The transmission may be a two speed or other multi-speed transmission. The second module is configured to operate in neutral while power demand is below a threshold, and to engage while the power demand exceeds the threshold. The second module may be configured to remain engaged for full-time four-wheel-drive operation.