Yanmar 1GM User Manual page 205

Chapter Ten
Transmission-KM Series
10
The input shaft on the transmission engages the drive
disc attached to the engine flywheel. Because this is a con -
stant-mesh transmission, engine power is transmi tted to
all gears . Power flows to the output shaft when the cone
clutch engages eithe r the fore....ard gear or the reverse gear.
In Figure 2, the cone clutch is shown engaged with the
forward gear. Because power flows from the input shaft
gear through the reverse idler gear to the reverse gear, the
reverse gear rotates in the opposi te direction of the for-
ward gear. When the cone clutch engages the reverse gear,
the output shaft rotates in reverse .
On Model KM2A, KM2C and KM 3A transmissions,
moving the shift lever (F igu re 3) rotates the shift shaft.
When the shift shaft rotates, the shifter slides the cone
clutch into engagement with the forwa rd or reverse gear,
or into neutral. When the shifter reaches the proper posi-
tion, the upper spring- loaded detent pin sits on a ramp that
O PERATION
Basic design is the same for all the transmissions with
the exception of the shifting mechanism. Transmissions
1 _
with a P suffix are equipped with a shifting device that en-
gages detent notches in the shifter housing. All other mod-
els use spring-loaded pins and a spring-loaded actuator
that engage detents and ramps on the shift shaft .
Refer to Chapter Three for maintenance information.
Tabl es 1-7 are located at the end of this chapter.
This chapter covers the Kanzaki KM2A , KM 2C,
KM2P, KM3A and KM3P marine transmissions that are
attached to Yanmar lGM, IGM IO, 2GM, 2GM20, 3GMD
and 3GM30 engines. Refer to Table I for a
cross-reference of engine and transmission mode ls. The
identification plate located on the transmission case (Fig-
ure I , typica l) specifies the transmission model.
The KM2 and KM3 series transmissions are inline
transmissions that provide forward and reverse direction.
All gears are constant mesh. A cone-type clutch engages
internally tape red gears to transmit power to the output
shaft. Oil contained in the transmission case lubricates the
interna l transmission components.