GUARD GP-LINES 4349392 - Caterpillar

Illustration 1 g02407637
View of the top of the transmission on the 770G (1) Number 1 clutch modulating valve (2) Number 2 clutch modulating valve (3) Number 3 clutch modulating valve (4) Number 4 clutch modulating valve (5) Number 5 clutch modulating valve (6) Number 6 clutch modulating valve (7) Number 7 clutch modulating valve (8) Main relief valve (9) Lubrication relief valve (transmission) (10) Modulating valve (torque converter lockup clutch)The transmission hydraulic control controls the oil pressure to the torque converter, the transmission clutches, and the lubrication circuits. The transmission hydraulic control also controls the flow of oil to the clutches. The transmission hydraulic control is installed on the top of the transmission planetary group. The transmission hydraulic control consists of the following components: main relief valve (8), clutch modulating valves (1) through (7), lubrication relief valve (9), and torque converter lockup clutch modulating valve (10) .Pressurized oil for the operation of the transmission hydraulic control flows from the power train gear pump to the transmission oil filter. The oil flows from the power train oil filter to the transmission inlet on the right side of the transmission. The oil flows through internal passages in the transmission housing in order to supply the components in the transmission hydraulic control with oil.The seven modulating valves are mounted on the top of the transmission. The seven transmission clutches have an individual modulating valve. In order to move the machine, two clutch solenoids must be energized. The modulating valves are used to directly modulate the oil pressure that is sent to each individual clutch.Table 1 provides the combination of the energized solenoids and engaged clutches for each forward speed and for reverse.
Table 1
Assignments for the Transmission Clutch    
Gear     Clutches    
1 2     3     4     5     6     7    
Reverse