Opel 1900 1973 Service Manual page 378

MAIN DRIVE GEAR (INPUT)
GEAR SHIFTER SLEEVE
GEAR SHIFTER SLEEVE CARRIER
F o u r t h S p e e d
After synchronizing speeds of the main drive gear
and mainshaft, the gear shifter sleeve shifts forward
and locks the main drive gear to the mainshaft
through the gear shifter sleeve carrier. This carrier is
internally splined to the gear shifter sleeve and is
externally splined to the mainshaft. The 3rd speed
gear, 2nd speed gear, and the 1st speed gear are all
idling. The reverse
any gear and, therefore, it is idle.
With a 4th speed gear ratio of 1.000: 1, the main drive
gear (input) must turn 1.000 revolutions for every
one revolution of the mainshaft (output).
POWER FLOW - 4th SPEED
Figure 78.5
idler gear is engaged with
MANUAL TRANSMISSION
GEAR SHIFTER SLEEVE
GEAR SHIFTER SLEEVE CARRIER
MAIN SHAFT (OUTPUT)