TM 5-3805-290-23-1
THEORY OF OPERATION - CONTINUED
0003 00
TRANSMISSION - CONTINUED
17.
Transmission Power Flow.
a.
Machine ECM determines proper clutches to engage based on inputs, including machine speed, engine speed, and
operator inputs.
b.
When engine is started, transmission oil pump pulls oil from sump and sends it through transmission oil filter.
Pressurized transmission oil flows from transmission oil filter to oil inlet in transmission housing, then through an
internal passage in transmission housing. Oil then flows through transmission relief valve into modulating valves.
c.
Oil in clutches that are not engaged is sent back to sump as return oil.
d.
Transmission relief valve controls pressure of pump oil supplied to modulating valves. Transmission relief valve
directs unneeded pump oil to torque converter as torque converter oil. Torque converter outlet oil flows through
torque converter outlet relief valve to oil cooler as lubrication oil. After oil cools, it flows through lubrication sys-
tem and to sump.
e.
Table 3 gives clutch combinations that are engaged for each forward and reverse speed. There is a modulating
valve for each clutch which directs pressurized oil to clutch to engage it. A solenoid is located on each modulating
valve which controls modulating valve spool. Machine ECM controls solenoids.
Table 3. Transmission Clutch Combination.
Third
Second
Fourth
Third
Second
Speed
Speed
Speed
First Speed
Speed
Speed
First Speed
Reverse
Reverse
Forward
Neutral
Reverse
Forward
Forward
Forward
Clutch 1
X
X
X
(forward
low)
X
Clutch 2
(forward
high)
Clutch 3
X
X
X
(reverse)
X
Clutch 4
(second
speed)
Clutch 5
X
X
X
X
(third speed
and fourth
speed)
Clutch 6
X
X
(first speed)
0003 00-60
