2002/11/04 A New Control Valve Improves the Service Life of the Transmission {3073} Caterpillar

Off-Highway Truck/Tractor:

776C (S/N: 2TK1-UP)

776D (S/N: 5ER1-UP; AFS1-UP)

777C (S/N: 4XJ1-UP)

777D (S/N: 3PR1-UP; AGC1-UP)

777D HAA (S/N: 2YW1-UP; AGY1-UP)

Description of Change: The individual clutch modulation control valve (ICM) for the certain Off-Highway Truck/Tractors has changed. The new ICM has a new pressure control valve. The new pressure control valve has different spools and different springs. The new pressure control valve requires different pressure settings. The pressure control valve was changed in order to address a problem with modulation in the transmissions. The problem with modulation can contribute to early hour failures of the number 4 clutch.

Adaptable To: The new 214-7741 Control Valve Gp (Individual Clutch Modulation) is a direct replacement for the 9W-8590 Control Valve Gp (Individual Clutch Modulation). The difference between the old ICM and the new ICM is the pressure control valve. The new 214-7740 Pressure Control Valve Gp is a direct replacement for the 6Y-3457 Pressure Control Valve Gp. The 214-7741 Control Valve Gp (Individual Clutch Modulation) is nonserviceable. The former 9W-8590 Control Valve Gp can be upgraded to the new 214-7741 Control Valve Gp by the replacement of the 6Y-3457 Pressure Control Valve Gp with the 214-7740 Pressure Control Valve Gp. The 214-7740 Pressure Control Valve Gp is effective with the following machines:

• 776D (S/N: AFS81-UP)

• 777D (S/N: AGC852, 866, 870-871, 894-895, 906-909, 916, 922-923, 927-928, 931-936, 938-940, 942-UP)

• 777D HAA (S/N: AGY81-UP)

In accordance with PI 30287, the new 214-7740 Control Valve must be installed in the following machines:

• 776D (S/N: AFS1-80)

• 777D (S/N: AGC1-851, 853-865, 867-869, 872-893, 896-905, 910-915, 917-921, 924-926, 929-930, 937, 941)

• 777D HAA (S/N: AGY1-80)

The new 214-7740 Pressure Control Valve Gp must be used in any transmission that is installed in any of the following machines: (S/N: AFS1-UP; AGC1-UP; AGY1-UP)

If the new pressure control valve is not used, the transmission will experience shifting problems. If the new pressure control valve is not used, the service life of the transmission will be reduced as well.

The 6Y-3457 Pressure Control Valve Gp will be serviced by the new 214-7740 Pressure Control Valve Gp. The new 214-7740 Pressure Control Valve Gp has different pressure settings. You must use the correct pressure settings when you install the newer valve into any of the following older machines.

• 776C (S/N: 2TK1-UP)

• 776D (S/N: 5ER1-UP)

• 777C (S/N: 4XJ1-UP)

• 777D (S/N: 3PR1-UP)

• 777D HAA (S/N: 2YW1-UP)

Use the following information for the correct settings of the new 214-7740 Pressure Control Valve Gp.

Table 1

Station (1)	A	B	C	E	F	G	H
Engaged Clutch	4	2	1	5	6	7	3
Type of Test	Pressure
Clutch Pressure At High Idle In Torque Converter Drive	-	2375 kPa (345 psi) (2)	2860 kPa (415 psi) (2)	-	2585 kPa (375 psi) (2)	2790 kPa (405 psi) (2)	-
Clutch Pressure At Low Idle In Torque Converter Drive	-	2375 kPa (345 psi) (2)	2790 kPa (405 psi) (2)	-	2585 kPa (375 psi) (2)	2760 kPa (400 psi) (2)	-
Clutch Pressure At High Idle in Direct Drive	1410 kPa (205 psi) (2)	2375 kPa (345 psi) (2)	2860 kPa (415 psi) (2)	2480 kPa (360 psi) (2)	2585 kPa (375 psi) (2)	2790 kPa (405 psi) (2)	1860 kPa (270 psi) (2)
Primary Clutch Pressure At Low Idle	515 kPa (75 psi) (3)	275 kPa (40 psi) (3)	345 kPa (50 psi) (3)	345 kPa (50 psi) (3)	415 kPa (60 psi) (3)	415 kPa (60 psi) (3)	550 kPa (80 psi) (3)

( 1 )	Station "D" is not used.
( 2 )	Tolerance is + 240 kPa (35 psi) or - 105 kPa (15 psi).
( 3 )	Tolerance is ± 40 kPa (± 6 psi).

Table 2

Shims for the Pressure Control Valve
Station (1)	A	B	C	E	F	G	H
Clutch that is engaged	4	2	1	5	6	7	3
The thickness of the shim	Pressure Change	Pressure Change	Pressure Change	Pressure Change	Pressure Change	Pressure Change	Pressure Change
5J-2721 Shim
0.13 mm (.005 inch)	13 kPa (1.9 psi)	16 kPa (2.4 psi)	20 kPa (2.9 psi)	17 kPa (2.4 psi)	17 kPa (2.4 psi)	18 kPa (2.7 psi)	18 kPa (2.6 psi)
6J-3993 Shim
0.25 mm (.010 inch)	26 kPa (3.8 psi)	33 kPa (4.8 psi)	41 kPa (5.9 psi)	33 kPa (4.8 psi)	33 kPa (4.8 psi)	37 kPa (5.4 psi)	35 kPa (5.1 psi)
4M-1751 Spacer
0.40 mm (0.016 inch)	42 kPa (6.1 psi)	53 kPa (7.7 psi)	65 kPa (9.4 psi)	53 kPa (7.7 psi)	53 kPa (7.7 psi)	59 kPa (8.6 psi)	56 kPa (8.2 psi)
5J-1036 Shim
0.80 mm (0.032 inch)	84 kPa (12.2 psi)	103 kPa (15.0 psi)	126 kPa (18.2 psi)	103 kPa (15.0 psi)	103 kPa (15.0 psi)	1144 kPa (16.6 psi)	109 kPa (15.8 psi)

( 1 )

Station (D) is not used.

Table 3

Specifications and Identification of the Components of the Pressure Control Valve
Load Piston Body for Station (1)	A	B	C	E	F	G	H
Thickness of the Load Piston Orifice	2.54 mm (0.100 inch)	2.54 mm (0.100 inch)	2.54 mm (0.100 inch)	4.58 mm (0.180 inch)	4.58 mm (0.180 inch)	4.58 mm (0.180 inch)	4.58 mm (0.180 inch)
Color of the Outer Spring of the Load Piston	Light Blue	Yellow	Light Green	Yellow	Yellow	Light Green	Light Green
Color of the Inner Spring of the Load Piston	Yellow	Light Blue	Light Blue	Light Blue	Light Blue	Yellow	Orange
Size of the Decay Orifice	1.57 mm (0.062 inch)	1.19 mm (0.047 inch)	-	1.57 mm (0.062 inch)	1.57 mm (0.062 inch)	-	1.40 mm (0.055 inch)
Color of the Decay Orifice	Green	Blue	-	Green	Green	-	Yellow
Overall Length of the Load Piston	58.5 mm (2.30 inch)	51.5 mm (2.03 inch)	51.5 mm (2.03 inch)	51.5 mm (2.03 inch)	51.5 mm (2.03 inch)	51.5 mm (2.03 inch)	58.5 mm (2.30 inch)

( 1 )

. Station "D" is not used.

Table 4

Primary Clutch Pressure
Station (1)		"A"	"B"	"C"	"E"	"F"	"G"	"H"
Clutch		No. 4	No. 2	No. 1	No. 5	No. 6	No. 7	No. 3
Speed Position	Engaged Clutches	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure
NEUTRAL-1	1	0	0	345 kPa (50 psi) (3)	0	0	0	0
NEUTRAL-2	1	0	0	345 kPa (50 psi) (3)	0	0	0	0
REVERSE	1 and 7	0	0	345 kPa (50 psi) (3)	0	0	415 kPa (60 psi) (3)	0
FIRST	2 and 6	0	275 kPa (40 psi) (3)	0	0	415 kPa (60 psi) (3)	0	0
SECOND	1 and 6	0	0	345 kPa (50 psi) (3)	0	415 kPa (60 psi) (3)	0	0
THIRD	3 and 6	0	0	0	0	415 kPa (60 psi) (3)	0	550 kPa (80 psi) (3)
FOURTH	1 and 5	0	0	345 kPa (50 psi) (3)	345 kPa (50 psi) (3)	0	0	0
FIFTH	3 and 5	0	0	0	345 kPa (50 psi) (3)	0	0	550 kPa (80 psi) (3)
SIXTH	1 and 4	515 kPa (75 psi) (3)	0	345 kPa (50 psi) (3)	0	0	0	0
SEVENTH	3 and 4	515 kPa (75 psi) (3)	0	0	0	0	0	550 kPa (80 psi) (3)

( 1 )	Station "D" is not used.
( 3 )	Tolerance is ± 40 kPa (± 6 psi).

Table 5

Clutch Pressure
Station (1)			"A"	"B"	"C"	"E"	"F"	"G"	"H"
Clutch			No. 4	No. 2	No. 1	No. 5	No. 6	No. 7	No. 3
Speed Position	Engaged Clutches	Governor Setting	psi	psi	psi	psi	psi	psi	psi
NEUTRAL-1	1	Low Idle	0	0	2790 kPa (405 psi) (2)	0	0	0	0
		High Idle	0	0	2860 kPa (415 psi) (2)	0	0	0	0
NEUTRAL-2	1	Low Idle	0	0	0	0	0	0	0
		High Idle	0	0	2860 kPa (415 psi) (2)	0	0	0	0
REVERSE	1 and 7	Low Idle	0	0	2790 kPa (405 psi) (2)	0	0	2760 kPa (400 psi) (2)	0
		High Idle	0	0	2860 kPa (415 psi) (2)	0	0	2790 kPa (405 psi) (2)	0
FIRST	2 and 6	Low Idle	0	2375 kPa (345 psi) (2)	0	0	2590 kPa (375 psi) (2)	0	0
		High Idle	0	2375 kPa (345 psi) (2)	0	0	2590 kPa (375 psi) (2)	0	0
SECOND	1 and 6	Low Idle	0	0	0	0	0	0	0
		High Idle	0	0	2860 kPa (415 psi) (2)	0	2590 kPa (375 psi) (2)	0	0
THIRD	3 and 6	Low Idle	0	0	0	0	0	0	0
		High Idle	0	0	0	0	2590 kPa (375 psi) (2)	0	1860 kPa (270 psi) (2)
FOURTH	1 and 5	Low Idle	0	0	0	0	0	0	0
		High Idle	0	0	2860 kPa (415 psi) (2)	2480 kPa (360 psi) (2)	0	0	0
FIFTH	3 and 5	Low Idle	0	0	0	0	0	0	0
		High Idle	0	0	0	2480 kPa (360 psi) (2)	0	0	1860 kPa (270 psi) (2)
SIXTH	1 and 4	Low Idle	0	0	0	0	0	0	0
		High Idle	1410 kPa (205 psi) (2)	0	2860 kPa (415 psi) (2)	0	0	0	0
SEVENTH	3 and 4	Low Idle	0	0	0	0	0	0	0
		High Idle	1410 kPa (205 psi) (2)	0	0	0	0	0	1860 kPa (270 psi) (2)

( 1 )	Station "D" is not used.
( 2 )	Tolerance is + 240 kPa (35 psi) or - 105 kPa (15 psi).