Copyright by Goodheart-Willcox Co., Inc.
208 Manual Drive Trains and Axles
Front
of
vehicle
Front
of
vehicle
Clutch or
torque converter
Clutch or
torque converter
Engine
Front drive
axles
Transaxle
Rear dead axle
Engine
Front drive
axles
Transaxle
Rear dead axle
A B
Figure 10-3. A—Front-wheel drive vehicle with a transverse-mounted engine. B—Front-wheel drive vehicle with a longitudinally
mounted engine.
move the vehicle in reverse. The differential portion of the
transaxle allows the vehicle to make turns while power is
being delivered. The differential assembly drives two CV
axles that turn the front drive wheels.
Operating the Manual Transaxle
From the driver’s point of view, operation of the
manual transaxle is identical to that of the rear-wheel drive
manual transmission. The driver selects gears through a
gearshift lever and manual clutch, pushes the clutch pedal
to disengage the clutch, and moves the gearshift lever to
the desired gear position. Moving the gearshift lever
operates the linkage that engages gears inside the trans-
mission. The driver then releases the clutch pedal to
engage the clutch. With the clutch engaged, the gears
transfer power through the transaxle to the output shaft.
The vehicle can then move in the selected gear position.
Construction and Internal Operation
There are two basic kinds of transaxle construction.
The type used depends on engine placement in the vehi-
cle. Engine installation can be transverse (crosswise) or
longitudinal (lengthwise), Figure 10-3. Major manual trans-
axle components include the following:
Manual transaxle shafts—support gears and directly
or indirectly transfer rotation from the clutch disc to
the transaxle differential assembly.
Transaxle transmission gears—transmit power and
provide a means of changing vehicle torque, speed,
and direction.
Synchronizers—bring certain transmission gears to
the same rotational speed as their associated shaft
before sliding in mesh with the gears and locking
them to the shaft. Synchronizers are used to prevent
gear clash. They operate in the same way as synchro-
nizers on rear-wheel drive manual transmissions.
Shift forks—pronged units for moving transmission gears
or synchronizers on their shaft for gear engagement.
Manual transaxle shift linkage—connects the gear-
shift lever to the shift forks. Linkage consists of shift
levers and rods or cables.
Manual transaxle differential assembly—receives
power from the transaxle transmission. The differen-
tial assembly contains differential drive gears, spider
gears, and side gears. It allows the vehicle to make
turns, allowing each drive wheel to rotate at a differ-
ent speed. Construction and operation is very similar
to that of a rear-wheel drive differential.
Manual transaxle case—encloses transaxle shafts,
gears, synchronizers, shift forks and linkage, and lubri-
cating oil. It also encloses the differential assembly.
Manual Transaxle Shafts
Manual transaxles contain several shafts, including
input, output, and reverse idler shafts. These shafts are
made of hardened steel. They must fit in the case with very
close tolerances. In some designs, the shafts rotate on ball
bearings, straight roller bearings, or needle bearings. Thrust
washers placed between gears on these shafts and the
transaxle case control endplay. In other designs, shafts
rotate on tapered roller bearings to control endplay.
Manual transaxle shafts are arranged differently in different
transaxles, but their basic function is the same.