Key
A Forward/Reverse Clutch Unit
A1 Forward Clutch
A2 Reverse Clutch
A3 Input Shaft
B Oil Pump
C Torque Converter
D Pressure Maintaining Valve
E Solenoid Valve
E1 Electrical Solenoid - Forward
E2 Electrical Solenoid - Reverse
H Oil Cooler
L Oil Strainer
N Oil Filter
P Pressure Relief Valve (Torque Converter)
Key - Power Take Off Components (If fitted)
M Output Shaft Assembly
J PTO Clutch
K Solenoid Valve
K1 Electrical Solenoid
R Brake Piston
R1 Brake Disc
Transmission
9803/7130 Issue 1
Syncro Shuttle Gearbox
Hydraulic and Electrical Operation
Oil is drawn from the gearbox sump via strainer L
by pump B. Pressurised oil from the pump is fed
through an internal passage via the filter N to the
pressure maintaining valve D, which maintains
pressure to the solenoid valve E for forward/reverse
clutch selection. Excess oil from the maintaining
valve flows back through casing cross drillings to
the torque converter C. Oil enters the converter
between the converter hub and the stator support,
and leaves between the stator and the input shaft.
Pressure in the converter is controlled by a relief
valve P which dumps excess oil from the converter
line back to the sump.
Oil from the torque converter flows out of the
transmission to the external oil cooler H, returning
at the rear of the transmission unit to pass through
the centre of the input shaft A3 for clutch
lubrication. Oil then returns to the sump.
Solenoid Valve (E) Operation
Pressurised oil at the solenoid valve E is used to
control the forward/reverse clutches A1 and A2.
Forward:
In the diagram, electrical solenoid E1 is energised
by the forward/reverse control lever in the cab.
Pressurised oil is diverted to the forward clutch A1
and forward is selected. A restrictor orifice in the
feed to the solenoid valve modulates the pressure
to the clutch to smooth engagement. At the same
time oil from reverse clutch A2 is diverted back to
the sump via solenoid valve E.
Reverse:
When the reverse is selected electrical solenoid E2
is energised and pressurised oil is diverted to the
reverse clutch A2. At the same time oil from clutch
A1 is diverted back to the sump
Neutral:
When neutral is selected (via the control lever or the
transmission dump button), the flow of the
pressurised oil is blocked at the solenoid valve. No
solenoids are energised and no clutches engaged.
For a further detailed description refer to
Forward/Reverse Clutch - Operation.
Power Take Off Operation (If fitted)
The PTO drive is controlled by a hydraulic clutch
similar in design to the forward/reverse clutches. A
hydraulic brake is also incorporated to prevent the
drive shaft rotating when the PTO is deselected.
Pressurised oil is fed directly to the PTO solenoid
control valve K.
PTO Drive Selected
When the PTO drive is selected via a switch in the
cab, the electrical solenoid K1 is enegised.
Pressurised oil is diverted to the clutch J, engaging
drive to the output shaft M. At the same time oil
from the brake piston R is diverted back to the
sump, releasing the brake.
PTO Drive Deselected
When the PTO drive is deselected via a switch in
the cab, the electrical solenoid K1 is de-energised.
Pressurised oil is diverted to the brake piston
forcing a brake disc R1 onto the output shaft
assembly M. At the same time oil from the clutch J
is diverted back to the sump, disengaging the
clutch.
3 - 6
3 - 6
Basic Operation
Section F Section F
To Next Page
Loading...
Need help?
General
