An axle assembly comprising: a housing assembly having an interior surface, a first lubricant passage, and a second lubricant passage; an input shaft that rotates about an axis and includes a first end and a flange portion disposed opposite the first end, the flange portion having a flange lubricant hole; a first roller bearing assembly that is disposed proximate the housing assembly and rotatably supports the input shaft; an output shaft that is at least partially disposed in the housing assembly and is configured to provide torque to a second axle assembly; a pinion that rotates about the axis and that has a pinion hole that receives the output shaft; second and third roller bearing assemblies (68, 70) that rotatably support the pinion; and an interaxle differential unit that is disposed in the housing assembly and is operatively coupled to the input shaft and the output shaft and compensates for rotational speed differences between the input shaft and the output shaft; wherein the first lubricant passage is disposed between the interior surface and the interaxle differential unit and has an inlet disposed opposite a first lubricant passage outlet that is disposed between the first end of the input shaft and the first roller bearing assembly, wherein the first lubricant passage is sloped such that the first lubricant passage is closer to the axis at the first lubricant passage outlet than at the inlet, wherein lubricant that exits the first lubricant passage outlet flows through the first roller bearing assembly and then passes through the flange lubricant hole to lubricate the interaxle differential unit, and characterized in that the second lubricant passage has a second lubricant passage outlet that is disposed between the second roller bearing assembly and the third roller bearing assembly, the first lubricant passage is disposed between the interior surface and the second lubricant passage, the second lubricant passage is disposed between the first lubricant passage and the pinion and provides lubricant to the second roller bearing assembly, and the inlet provides lubricant to the first and second lubricant passages (92, 94). a housing assembly having an interior surface, a first lubricant passage, and a second lubricant passage; an input shaft that rotates about an axis and includes a first end and a flange portion disposed opposite the first end, the flange portion having a flange lubricant hole; a first roller bearing assembly that is disposed proximate the housing assembly and rotatably supports the input shaft; an output shaft that is at least partially disposed in the housing assembly and is configured to provide torque to a second axle assembly; a pinion that rotates about the axis and that has a pinion hole that receives the output shaft; second and third roller bearing assemblies (68, 70) that rotatably support the pinion; and an interaxle differential unit that is disposed in the housing assembly and is operatively coupled to the input shaft and the output shaft and compensates for rotational speed differences between the input shaft and the output shaft; wherein the first lubricant passage is disposed between the interior surface and the interaxle differential unit and has an inlet disposed opposite a first lubricant passage outlet that is disposed between the first end of the input shaft and the first roller bearing assembly, wherein the first lubricant passage is sloped such that the first lubricant passage is closer to the axis at the first lubricant passage outlet than at the inlet, wherein lubricant that exits the first lubricant passage outlet flows through the first roller bearing assembly and then passes through the flange lubricant hole to lubricate the interaxle differential unit, and characterized in that the second lubricant passage has a second lubricant passage outlet that is disposed between the second roller bearing assembly and the third roller bearing assembly, the first lubricant passage is disposed between the interior surface and the second lubricant passage, the second lubricant passage is disposed between the first lubricant passage and the pinion and provides lubricant to the second roller bearing assembly, and the inlet provides lubricant to the first and second lubricant passages (92, 94).