Said speed changing operation of said {HEAD ~ either one transmission mechanism} started in the step establishes a third shift position in {TAIL ~ the automatic transmission} 
Said speed changing operation of said { HEAD ~ either one transmission mechanism } started in the step establishes a third shift position in { TAIL ~ the automatic transmission }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL