Oil cooling of clutch package

An oil cooling system for a stacked plate type clutch package assembly, the assembly including a stacked plate arrangement of alternating separator plates and clutch plates housed within a retainer and the stacked plate arrangement, when assembled, creates a path for oil flow therethrough, wherein the oil cooling system comprises:

• an oil supply delivery arrangement positioned at a central shaft of the clutch package assembly for producing radially outward oil flow;
• and
• a flow passage structure arranged relative to the retainer and stacked plate arrangement to provide a secondary oil path for the radially outward oil flow additional to the flow path through the stacked plate arrangement, wherein said radially outward oil flow through the secondary flow path comes into heat exchange contact initially with an outermost surface of the separator plates, said flow passage structure comprising a plurality of passages each providing a flow path along an axial wall of the retainer and a radial passage in the retainer, said radial passage arranged in fluid communication with said oil supply delivery arrangement and said plurality of passages to allow oil flow from said oil supply delivery arrangement to said plurality of passages and into heat exchange contact initially with the outermost surface of the separator plates for cooling of the plates.