are either made Integral or keyed on, they also rotate at
backward, forward, and sidewise. The end of the lever
the time the clutch is engaged. The transmission main
below the ball fulcrum engages both slots, but there Is an
shaft Is held in line with the Input shaft by a pilot bearing
Interlock device (usually a ball or pin engaging notches in
at its front end, which allows It to rotate or come to rest
each shifter shaft) that permits one shifter shaft to move
independently of the Input shaft. The main shaft,
at a time, but not both. This prevents two speeds being
countershaft, and Input shafts, with their respective
engaged at once. When the control lever handle Is
pressed to the left, the slot In the first-and-reverse shifter
in the transmission case.
shaft Is engaged and the fork can be moved backward or
c. Shift Rails and Forks. Shift rails and forks are
forward. After the first-and-reverse shifter shaft has been
returned to the neutral position, the control lever can be
provided to move the gears when the control lever Is
pressed to the right and the second-and-third shifter shaft
moved by the driver to change speeds.
and fork can be moved forward or backward. The shifter
shafts are held In the different speeds and the neutral
position by spring-loaded balls or poppets engaging
transmission described above Is operated by a control
notches In the shifter shafts.
lever assembled to, and extending from, the control
housing (fig. 22-1). The lever has a ball fulcrum fitting
22-7. Power Flow. The following paragraphs describe
into a socket In the housing. It Is kept from rotating by a
the power flow of the sliding gear transmission.
setscrew entering a slot In the side of the ball fulcrum but
Is free to move
Figure 22-1 Transmission Shifting Mechanism and Control Lever.
Change 1 22-2