Transmission auxiliary unit shift inhibitor

A shift inhibitor apparatus for a multiple speed transmission main section, the transmission including an input shaft and an output shaft, the transmission main section having a plurality of selectively engageable ratios, and the transmission also having a range section shiftable between a range high ratio and a range low ratio, the shift inhibitor comprising:

• an interlock moveable between a locked condition and a released condition, wherein said interlock selectively restricts rotation of a shift member when in the locked condition, thereby preventing a gear shift in the transmission main section;
• and
• a range sensor valve, wherein said range sensor valve selectively detects a range shift of the range section, said range sensor valve selectively causes said interlock to be positioned in the released condition upon detection of a completed range shift.

A method of inhibiting a shift in a multispeed transmission main section, wherein the multispeed transmission includes an input shaft, an output shaft, and a range section shiftable between a range high ratio and a range low ratio, and the main section has a plurality of selectable gear ratios, the method comprising the steps of:

• detecting a range section engaged ratio;
• and
• preventing a main section shift, wherein said step of preventing is effected through the application of a working fluid.