Double swap kickdown shift control

A method of performing a double swap downshift from a first gear ratio to a second, lower gear ratio in a transmission having a main box and a compounder box coupled to the main box, the main box having a first plurality of clutches coupled to a transmission input shaft, and the compounder box having a second plurality of clutches coupled to a compounder main shaft, the transmission having a target ratio at which said transmission input shaft rotates relative to said compounder main shaft when operating in said lower gear ratio, the method comprising:

• fully releasing a first clutch of said second plurality of clutches and partially applying a second clutch of said second plurality of clutches;
• partially releasing a first clutch of said first plurality of clutches;
• modulating the release of said first clutch of said first plurality of clutches, thereby, permitting said first clutch of said first plurality of clutches to slip at a rate such that the rotations per minute (RPM) of said transmission input shaft exceed the target ratio by a predetermined overshoot amount;
• fully applying said second clutch of said second plurality of clutches;
• partially applying a second clutch of said first plurality of clutches;
• fully applying said second clutch of said first plurality of clutches;
• and
• fully releasing said first clutch of said first plurality of clutches.