Jeep XJ. Manual — part 396
FRONT CLUTCH
DESCRIPTION
The front clutch assembly (Fig. 43) is composed of
the front clutch retainer, pressure plate, four clutch
plates, four driving discs, piston, piston return
spring, return spring retainer, and snap rings. The
front clutch is the forwardmost component in the
transmission geartrain and is directly behind the oil
pump and is considered a driving component.
NOTE: The number of discs and plates may vary
with each engine and vehicle combination.
OPERATION
To apply the clutch, pressure is applied between
the clutch retainer and piston. The fluid pressure is
provided by the oil pump, transferred through the
control valves and passageways, and enters the
clutch through the hub of the reaction shaft support.
With pressure applied between the clutch retainer
and piston, the piston moves away from the clutch
retainer and compresses the clutch pack. This action
applies the clutch pack, allowing torque to flow
through the input shaft into the driving discs, and
into the clutch plates and pressure plate that are
lugged to the clutch retainer. The waved snap ring is
used to cushion the application of the clutch pack. In
some transmissions, the snap ring is selective and
used to adjust clutch pack clearance.
When pressure is released from the piston, the
spring returns the piston to its fully released position
and disengages the clutch. The release spring also
helps to cushion the application of the clutch assem-
bly. When the clutch is in the process of being
released by the release spring, fluid flows through a
vent and one–way ball–check–valve located in the
clutch retainer. The check–valve is needed to elimi-
nate the possibility of plate drag caused by centrifu-
gal force acting on the residual fluid trapped in the
clutch piston retainer.
Fig. 43 Front Clutch
1 – RETAINER HUB SEAL
2 – CLUTCH PISTON
3 – PISTON SPRING
4 – SPRING RETAINER SNAP RING
5 – CLUTCH DISCS
6 – PRESSURE PLATE
7 – SNAP RING (WAVED)
8 – CLUTCH PLATES
9 – SPRING RETAINER
10 – PISTON SEAL
11 – FRONT CLUTCH RETAINER
21 - 120
AUTOMATIC TRANSMISSION—30RH
XJ
DESCRIPTION AND OPERATION (Continued)
REAR CLUTCH
DESCRIPTION
The rear clutch assembly (Fig. 44) is composed of
the rear clutch retainer, pressure plate, three clutch
plates, four driving discs, piston, Belleville spring,
and snap rings. The Belleville spring acts as a lever
to multiply the force applied on to it by the apply pis-
ton. The increased apply force on the rear clutch
pack, in comparison to the front clutch pack, is
needed to hold against the greater torque load
imposed onto the rear pack. The rear clutch is
directly behind the front clutch and is considered a
driving component.
NOTE: The number of discs and plates may vary
with each engine and vehicle combination.
OPERATION
To apply the clutch, pressure is applied between
the clutch retainer and piston. The fluid pressure is
provided by the oil pump, transferred through the
control valves and passageways, and enters the
clutch through the hub of the reaction shaft support.
With pressure applied between the clutch retainer
and piston, the piston moves away from the clutch
retainer and compresses the clutch pack. This action
applies the clutch pack, allowing torque to flow
through the input shaft into the driving discs, and
into the clutch plates and pressure plate that are
lugged to the clutch retainer. The waved snap ring is
used to cushion the application of the clutch pack. In
some transmissions, the snap ring is selective and
used to adjust clutch pack clearance.
Fig. 44 Rear Clutch
1 – PISTON SPRING
2 – REAR CLUTCH PISTON
3 – CLUTCH PISTON SEALS
4 – OUTPUT SHAFT THRUST WASHER (METAL)
5 – INPUT SHAFT SNAP RING
6 – REAR CLUTCH RETAINER
7 – INPUT SHAFT
8 – REAR CLUTCH THRUST WASHER (FIBER)
9 – SHAFT FRONT SEAL RING (TEFLON)
10 – SHAFT REAR SEAL RING (METAL)
11 – CLUTCH PACK SNAP RING (SELECTIVE)
12 – RETAINER SEAL RING
13 – CLUTCH PLATES (3)
14 – TOP PRESSURE PLATE
15 – CLUTCH DISCS (4)
16 – BOTTOM PRESSURE PLATE
17 – WAVE SPRING
XJ
AUTOMATIC TRANSMISSION—30RH
21 - 121
DESCRIPTION AND OPERATION (Continued)
When pressure is released from the piston, the
spring returns the piston to its fully released position
and disengages the clutch. The release spring also
helps to cushion the application of the clutch assem-
bly. When the clutch is in the process of being
released by the release spring, fluid flows through a
vent and one–way ball–check–valve located in the
clutch retainer. The check–valve is needed to elimi-
nate the possibility of plate drag caused by centrifu-
gal force acting on the residual fluid trapped in the
clutch piston retainer.
OVERRUNNING CLUTCH
DESCRIPTION
The overrunning clutch (Fig. 45) consists of an
inner race, an outer race (or cam), rollers and
springs, and the spring retainer. The number of roll-
ers and springs depends on what transmission and
which overrunning clutch is being dealt with.
OPERATION
As the inner race is rotated in a clockwise direction
(as viewed from the front of the transmission), the
race causes the rollers to roll toward the springs,
causing them to compress against their retainer. The
compression of the springs increases the clearance
between the rollers and cam. This increased clear-
ance between the rollers and cam results in a free-
wheeling condition. When the inner race attempts to
rotate counterclockwise, the action causes the rollers
to roll in the same direction as the race, aided by the
pushing of the springs. As the rollers try to move in
the same direction as the inner race, they are
wedged between the inner and outer races due to the
design of the cam. In this condition, the clutch is
locked and acts as one unit.
PLANETARY GEARSET
DESCRIPTION
The planetary gearsets (Fig. 46) are designated as
the front and rear planetary gear assemblies and
located in such order. A simple planetary gearset con-
sists of three main members:
• The sun gear which is at the center of the system.
• The planet carrier with planet pinion gears
which are free to rotate on their own shafts and are
in mesh with the sun gear.
• The annulus gear, which rotates around and is
in mesh with the planet pinion gears.
NOTE: The number of pinion gears does not affect
the gear ratio, only the duty rating.
OPERATION
With any given planetary gearset, several condi-
tions must be met for power to be able to flow:
• One member must be held.
• Another member must be driven or used as an
input.
• The third member may be used as an output for
power flow.
• For direct drive to occur, two gear members in
the front planetary gearset must be driven.
NOTE: Gear ratios are dependent on the number of
teeth on the annulus and sun gears.
Fig. 45 Overrunning Clutch
1 – OUTER RACE (CAM)
2 – ROLLER
3 – SPRING
4 – SPRING RETAINER
5 – INNER RACE (HUB)
Fig. 46 Planetary Gearset
1 – ANNULUS GEAR
2 – SUN GEAR
3 – PLANET CARRIER
4 – PLANET PINIONS (4)
21 - 122
AUTOMATIC TRANSMISSION—30RH
XJ
DESCRIPTION AND OPERATION (Continued)
BANDS
DESCRIPTION
KICKDOWN (FRONT) BAND
The kickdown, or “front”, band (Fig. 47) holds the
common sun gear of the planetary gear sets. The
front (kickdown) band is made of steel, and faced on
its inner circumference with a friction–type lining.
One end of the band is anchored to the transmission
case, and the other is acted on with a pushing force
by a servo piston. The front band is a single–wrap
design (the band does not completely encompass/
wrap the drum that it holds).
LOW/REVERSE (REAR) BAND
The low/reverse band, or “rear”, band (Fig. 48) is
similar in appearance and operation to the front
band. The rear band of the 32RH is slightly different
in that it does not use a link bar, but is acted directly
on by the apply lever. This is referred to as a double–
wrap band design (the drum is completely encom-
passed/wrapped by the band). The double–wrap band
provides a greater holding power in comparison to
the single–wrap design.
OPERATION
KICKDOWN (FRONT) BAND
The kickdown band holds the common sun gear of
the planetary gear sets by applying and holding the
front clutch retainer, which is splined to the sun gear
driving shell, and in turn splined directly to the sun
gear. The application of the band by the servo is typ-
ically done by an apply lever and link bar.
LOW/REVERSE (REAR) BAND
The rear band holds the rear planet carrier sta-
tionary by being mounted around and applied to the
low/reverse drum.
SERVOS
DESCRIPTION
KICKDOWN (FRONT) SERVO
The kickdown servo (Fig. 49) consists of a two–land
piston with an inner piston, a piston rod and guide,
and a return spring. The dual–land piston uses seal
rings on its outer diameters and an O–ring for the
inner piston.
LOW/REVERSE (REAR) SERVO
The rear (low/reverse) servo consists of a single
stage or diameter piston and a spring loaded plug.
The spring is used to cushion the application of the
rear (low/reverse) band.
OPERATION
KICKDOWN (FRONT) SERVO
The application of the piston is accomplished by
applying pressure between the two lands of the pis-
ton. The pressure acts against the larger lower land
to push the piston downward, allowing the piston rod
to extend though its guide against the apply lever.
Release of the servo at the 2–3 upshift is accom-
plished by a combination of spring and line pressure,
acting on the bottom of the larger land of the piston.
Fig. 47 Front Band
1 – FRONT BAND
2 – TRANSMISSION HOUSING
Fig. 48 Rear Band
1 – PLANETARY GEARTRAIN
2 – REAR BAND
3 – LEVER
4 – SERVO
5 – ADJUSTER
XJ
AUTOMATIC TRANSMISSION—30RH
21 - 123
DESCRIPTION AND OPERATION (Continued)
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст