Clean grain conveyor for an agricultural combine

A clean grain conveyor for an agricultural combine (10) having a side wall (200), comprising:

• an auger conveyor (52) for conveying clean grain that extends laterally and horizontally in a lower portion of the combine, the auger conveyor (52) further comprising auger flights (204) having a longitudinal axis and disposed in a shallow trough (68);
• a paddle elevator (53) having a grain inlet is disposed to convey clean grain to a grain tank (30) of the agricultural combine (10) from the grain inlet;
• and
• a transition tube (218) having two ends, an inside height, an inside surface and an entire axial length, said two ends including a first end that defines a first triangular aperture (223) and a second end that defines a second aperture (227), wherein the first triangular aperture is fixed to a corresponding triangular aperture (214) in the side wall (200) and through which said auger flights (204) extend, and further wherein the second aperture is fixed to the grain inlet wherein radially outermost side surface portions (400), (402) of the inside surface of the transition tube (218) taper inwardly in a radial direction.