Page 89 of 1807
27 SUPRAÐNEW FEATURES
Construction
The helical gear type torque±sensing LSD consists of a differential case, 9 planet gears, 2 side gears and 4 thrust
washers.
Planet gears mesh with one another as a pair, and each gear of the pair meshes with the side gear on its right or left
side.
The planet gears are supported by the hole that is provided in the differential case. They are constructed so that they
revolve while rotating over the side gear.
Operation
1) Straight±Ahead Operation
Since side gears (left and right) and planet gears are rotating together with the differential case as a unit when the
vehicle is running straight±forward, the driving force is transmitted from the ring gear to the differential case, planet
gears and side gears.
Page 90 of 1807

28SUPRAÐNEW FEATURES
2) Cornering
Supposing that the differential case is not moving, rotating the left side gear counterclockwise, causes planet gear
A (which meshes with the left side gear) to rotate clockwise.
Furthermore, planet gear B, which is paired with planet gear A, rotates counterclockwise, causing the right side gear
(which meshes with planet gear B) to rotate clockwise.
Therefore the left and right side gears rotate in the opposite direction each other, thus accomplishing a motion
differential.
3) Limited Slip Differential Operation
Limited slip is accomplished primarily b the friction that is generated between the planet gear's tooth tips and the
differential case's inner wall, and the friction that is generated between the side gear end face and the thrust washer.
The principle of limited slip enables the resultant reaction force F1 (which is created by the meshing reaction of the
planet gear and the side gear and the meshing reaction of the planet gears themselves) to push the planet gear in the
direction of the differential case in proportion to the input torque.
Due to the reaction force F1, the friction force u F2 (which is generated between the side gear end face and the thrust
washer) applies a force to cancel out the rotational difference between the side gears themselves as well as between
the side gear and the differential case.
Page 91 of 1807

29 SUPRAÐNEW FEATURES
DRIVE SHAFT
The drive shaft outboard joint of the 2JZ±GE engine model has been changed from the cross±groove type CJV
(Constant±Velocity Joint) to the Rzeppa type CVJ.
As in the '96 model, the 2JZ±GTE engine model uses the drive shaft consisting of cross±groove type CVJs for both
the inboard and outboard joints.
BRAKES
1. General
The size of the master cylinder for the 2JZ±GTE engine model has been increased to realize excellent brake feeling.
The ABS actuator has been changed from the conventional three±position solenoid valves to a combination of
compact two±position solenoid valves, thus achieving a compact and lightweight configuration.
3±channel type ABS with 4±speed sensor is used on the 2JZ±GE engine model.
4±channel type ABS with 4±speed sensors and linear type deceleration sensor is used on the 2JZ±GTE engine
model.
Specifications
Model
'97 Model '96 Model
Engine Type2JZ GE2JZ GTE2JZ GE2JZ GTEItem2JZ±GE2JZ±GTE2JZ±GE2JZ±GTE
MasterTypeTandemuuuMaster
CylinderDia. mm (in.)25.4 (1.00)26.9 (1.06)25.4 (1.00)u
ABS Type
3 Channel Type
ABS with
4±Speed Sensors
4 Channel Type
ABS with
4±Speed Sensors
and Linear Type
Deceleration Sensor4±Channel Type
ABS with 4±Speed
Sensor and Lateral
Acceleration Sensors
u
ABS Type Actuator
6 Two Position
Solenoid Valves8 Two Position
Solenoid Valves4 Three Position
Solenoid Valvesu
Page 92 of 1807
30SUPRAÐNEW FEATURES
2. ABS
General
The ABS (Anti±Lock Brake System) is designed to control the brake fluid pressure of the brake wheel cylinder to
help prevent wheel lock±up in instances of panic braking, and thus maintaining vehicle directional stability and
control.
System Diagram
Page 93 of 1807
31 SUPRAÐNEW FEATURES
Wiring Diagram
Page 94 of 1807

32SUPRAÐNEW FEATURES
Layout of Components
Construction and Operation
1) Deceleration Sensor
The 2JZ±GTE engine model uses a linear type deceleration sensor to detect the deceleration rate in the vehicle's
longitudinal direction and the acceleration rate in the vehicle's lateral direction.
Accordingly, the ABS in able to determine the vehicle's cornering condition and various road surface conditions to
achieve a finely cornering control.
The basic construction and operation are the same as those of the '97 RAV4 4WD 2±door model. For details, see '96
RAV4 New Car Features (Pub. No. NCF124U), page 70.
2) ABS Actuator
a. General
The ABS actuator consists of 6 or 8 two±position solenoid valves, 2 pumps, 2 reservoirs and a motor. The table below
compares the actuator against that of the '96 model.
Comparison of ABS Actuators
Model
'97 Model '96 Model
Engine Type2JZ GE2JZ GTE2JZ GE 2JZ GTEEngine Type2JZ±GE2JZ±GTE2JZ±GE, 2JZ±GTE
Actuator Type2±Position2±Position3±Position
ComponentSolenoid ValvesSolenoid ValvesSolenoid Valves
Control Unit
6 Two±Position
Solenoid Valves
(3 pressure holding
valves and
3 pressure
reduction valves)8 Two±Position
Solenoid Valves
(4 pressure holding
valves and
4 pressure
reduction valves)
4 Three±Position
Solenoid Valves
Page 95 of 1807
33 SUPRAÐNEW FEATURES
b. Hydraulic Circuit
Page 96 of 1807

34SUPRAÐNEW FEATURES
c. Operation
The hydraulic system of the ABS has 3 or 4 circuits. Although the hydraulic circuit described below has 1 circuit,
it is applicable to other circuits as well.
i) During Normal Braking (ABS not Activated)
During normal braking, the ABS is not activated and
the ECU dose not send control signal.
When the brake pedal is depressed, the fluid passes
from port A to port B, and then flows to the brake
wheel cylinder.
When the brake pedal is released, brake fluid returns
from the brake wheel cylinder to the master cylinder
through port B to port A and No. 1 Check Valve.
Condition of Actuator
Part Name
Signal from
ABS ECUOperation
Pressure
Holding ValveOFFPort AOpen
Pressure
Reduction
Valve
OFFPort BClosed
Pump MotorOFFRotating
Hydraulic Circuit
ii) During Emergency Braking (ABS Activated)
Pressure Reduction Mode
When the wheel about to lock , the control signal from
the ECU causes port A to close and port D to open,
thus engaging the pressure reduction mode.
At this time the brake fluid flows from the wheel
cylinder, through ports C and D, to the reservoir
reducing the wheel pressure.
At the same time the brake fluid is pumped and
returned to the master cylinder.
Condition of Actuator
Part Name
Signal from
ABS ECUOperation
Pressure
Holding ValveONPort AClosed
Pressure
Reduction
Valve
ONPort DOpen
Pump MotorONRotating
Hydraulic Circuit