Land Rover Lesson 2 Auto Trans Coolingine Rover Manual

The sprags are located in a cage which is a spring which
holds the sprags in the wedge direction and maintains
them in contact with the inner and outer races.
Referring to the illustration, the sprags are designed so
that the dimension B is larger than the distance between
the inner and outer race bearing surfaces. When the
outer race rotates in a clockwise direction, the sprags
twist and the edges across the dimension B wedge
between the races, providing a positive drive through
each sprag to the inner...

The lock-up clutch is a hydro-mechanical device which
eliminates torque converter slip, improving fuel
consumption. The engagement and disengagement is
controlled by the TCM to allow a certain amount of
controlled slip. This allows a small difference in the
rotational speeds of the impeller and the turbine which
results in improved shift quality. The lock-up clutch
comprises a piston and a clutch friction plate.
In the unlocked condition, the oil pressure supplied to
the piston chamber and the turbine...

Securing ring1
Shaft oil seal2
O-ring seal3
Pump housing4
Ring gear5
Crescent spacer6
Roller bearing7
Impeller8
Centring pin9
Spring washer10
Outlet port (high pressure)11
Inlet port (low pressure)12
The pump comprises a housing, a crescent spacer, an
impeller and a ring gear. The housing has inlet and outlet
ports to direct flow and is located in the intermediate
plate by a centring pin. The pump action is achieved by
the impeller, ring gear and crescent spacer.
The crescent spacer is fixed in its...

reaches the outlet port. When the teeth pass the end of
the spacer the pressurised fluid is passed to the outlet
port.
The fluid emerging from the outlet port is passed
through the fluid pressure control valve. At high
operating speeds the pressure control valve maintains
the output pressure to the gearbox at a predetermined
maximum level. Excess fluid is relieved from the
pressure control valve and is directed, via the main
pressure valve in the valve block, back to the pump inlet
port. This provides a...

ZF 6HP26 Automatic Transmission – Mechatronic Valve Block
Position switch1
Sliding block2
Selector spool valve3
Position switch assembly4
Automatic TransmissionLesson 2 – Powertrain
259Technical Training (G421157) 

Electronic Pressure Regulator Solenoid (EPRS)
6
5
Solenoid Valve 16
EPRS 47
EPRS 58
EPRS 39
EPRS 210
EPRS 111
Electrical connector12
Transmission Control Module (TCM)13
Valve housing14
Valve plate15
Torque converter retaining valve16
Clutch return valve17
Element seal18
Pressure regulator dampers19
Intermediate plate20
(G421157) Technical Training260
Lesson 2 – PowertrainAutomatic Transmission 

ZF 6HP26 Automatic Transmission – Valve Housing Components
Selector spool valve1
Lubricating valve2
Torque converter pressure valve3
System pressure valve4
Automatic TransmissionLesson 2 – Powertrain
261Technical Training (G421157) 

Torque converter clutch valve5
Retaining valve – Clutch E6
Clutch valve E7
Clutch valve A8
Valve housing9
Bolts10
Retaining valve – Clutch A11
Retaining valve – Clutch B12
Pressure reducing valve13
Shift valve 114
Retaining valve – Brake D15
Shift valve 216
Damper17
Electronic Pressure Regulator Solenoid (EPRS)
6
18
Solenoid valve 119
EPRS 420
EPRS 521
EPRS 222
EPRS 323
EPRS 124
ZF 6HP26 Automatic Transmission – Valve Plate Components
Retaining valve – Brake D21
Clutch valve – Brake D22
Clutch valve B3...

Electronic Pressure Regulator Solenoids (EPRS)
Six Electronic Pressure Regulator Solenoids (EPRS)
are located in the valve block. The solenoids are
controlled by Pulse width Modulation (PWM) signals
from the TCM. The solenoids convert the electrical
signals into hydraulic control pressure proportional to
the signal to actuate the spool valves for precise
transmission operation.
The following table shows EPRS and their associated
functions:
FunctionEPRS
Clutch A1
Clutch B2
Clutch C3
Brake clutches D and...

Control Solenoid
A shift control Solenoid Valve (SV) is located in the
valve block. The solenoid is controlled by the TCM and
converts electrical signals into hydraulic control signals
to control clutch application.
The shift control solenoid is an open/closed, on/off
solenoid which is controlled by the TCM switching the
solenoid to earth. The TCM also supplies power to the
solenoid. The TCM energises the solenoid in a
programmed sequence for clutch application for gear
ratio changes and shift control....