TRUCK SERVICE MANUAL
TRANSMISSION
HT 700D SERIES TRANSMISSIONS
Para 2-912-11
ten clutch plates, a piston, a forward clutch hub and a
retained in the converter housing by six bolts. Driven
fourth-clutch driving hub.
gear 6 is supported in the pump body by gear shafts 5.
b. Operation (A, foldout 8). When the converter
(2) The clutch housing contains an oil
pump rotates, its rear hub drives pump drive gear 4.
collector ring attached to its outer diameter and works in
conjunction with a pitot tube to produce front governor
Gear 4 is in mesh with driven gear ASSEMBLY 6. Thus,
pressure.
as the gears rotate, oil is drawn into the inlet port and is
carried between the pump housing and the gear teeth to
The clutch housing contains the forward clutch piston,
the outlet s id e of the pump into the hydraulic system.
positioned inside the housing in its bore, retained by
twenty springs, a spring retainer and a snapring.
2-10. FORWARD SUPPORT AND VALVE ASSEMBLY
(3) Five of the clutch plates are internal-
The forward support and valve assembly is
splined, while the remaining five are external-tanged.
connected to the rear of the converter housing It
The internal-splined plates are attached to the forward
provides support for the forward clutch and turbine shaft.
clutch hub. The external-tanged plates are attached to
Contained within the support assembly are three valves
the internal grooves of the forward clutch housing.
main pressure regulator valve assembly 3 (B, foldout
10), lockup shift valve 8, and converter bypass valve 14.
c. Operation (A, foldout 11)
2-11. FORWARD CLUTCH AND TURBINE SHAFT (A,
(1) Clutch housing and shaft assembly 5
foldout 11)
rotate when the converter turbine rotates. Fourth-clutch
driving hub 23 also rotates causing the internal-splined
a. Function
plates of the fourth-clutch pack to rotate.
(2) The forward clutch has multiple functions.
(2) When hydraulic pressure is directed to the
When engaged with low clutch, it produces first gear.
front side of piston 13, clutch plates 21 and 22 are
When engaged with first clutch, second, third or fourth
compressed together. This locks forward-clutch hub 20
clutches, it produces second, third, fourth or fifth gears,
to the forward clutch housing. Since hub 20 is splined to
in that sequence.
the transmission main shaft, the shaft will rotate with the
hub, at input speed.
b. Description
(3) The simultaneous application of two
THE MODEL HAS A CLUTCH HOUSING WITH A
clutches is necessary to produce one forward or one
TURBINE SHAFT ATTACHED
reverse gear. The forward clutch is applicable only in
forward gears (refer to b .(1), (2), above). When the
converter turbine rotates, and the forward clutch is
applied, the main shaft drives the components of the
gear unit which in turn drive the output shaft.
(4) Rotation of the oil (pitot)collector ring
directs oil against the front pitot tube any time the
converter turbine rotates. Thus, an increase in turbine
speed produces a proportional increase in front governor
pressure.
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