Bench Test Procedure for a 770 and 772 Off-Highway Truck Transmission{3030, 3073} Caterpillar

Off-Highway Truck/Tractor:

770 (S/N: BZZ1-UP)

772 (S/N: RLB1-UP)

Introduction

Table 1

Revision	Summary of Changes in REHS3497
02	Updated Introduction. Added Section ""Stall Speed Option" ". Updated Harness & Solenoid Test information.
01	Updated Introduction. Added Canceled Replaced Part Numbers statement.

© 2015 Caterpillar All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law. Information contained in this document is considered Caterpillar: Confidential Yellow.

This special instruction contains the necessary information that is required to bench test-specific transmission arrangements. Refer to Table 2 for the correct arrangements. Bench testing the transmission ensures correct assembly and operation of the component. Rotating a transmission provides the most conclusive evaluation. This procedure allows the dealer to ensure that the transmission will operate properly in the machine. The specifications in this guideline are specific to bench testing the component. Every effort has been made in order to provide the most current information that is known to Caterpillar. Continuing improvement and advancement of product design might have caused changes to your product which are not included in this publication. This guideline must be used with the latest technical information that is available from Caterpillar.

For questions or additional information concerning this guideline, submit a form for feedback in the Service Information System. In order to address an urgent need, use the following resources to communicate your request to Caterpillar Repair Process Engineering:

• Cat Dealer Techinical Communicator

• Dealer Solution Network

• Cat Technical Representative

• Knowledge Network

Table 2

Machine Model	Transmission Arrangement
770	294-5560
772	294-5560

Canceled Part Numbers and Replaced Part Numbers

This document may not include canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Collecting the Test Data

Since conditions vary for each test bench, use the data that is collected from your test bench. The collected data is used to compare test results. The data should be collected and maintained by the operator.

Data from each transmission arrangement is collected and stored. Averages from each transmission arrangement are used in order to compare values on portions of this transmission test. Always compare data that is collected from the same transmission arrangement that is being tested. Averages for the last 20 transmission arrangements should be maintained.

Illustration 1	g02139237

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Personal injury or death can result from escaping fluid under pressure. Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause serious injury and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak.

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Hot oil and components can cause personal injury. Do not allow hot oil or components to contact skin.

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Personal injury or death can result from not following the proper procedures. To avoid the possibility of injury or death, follow the established procedure.

Tools Needed

Note: Pressures will be sensitive to tooling setup. The diameter of the hose, the diameter of a fitting, and additional filtering can affect pressure. The required tools that are listed in Table 3 were used in order to develop this test procedure.

Table 3

Required Tools
Tool	Part Number	Part Description	Qty
A	1U-9722	Load Binder As	3
B	4C-4627	Adapter	1
C	4C-4336	Adapter	1
D	9U-7445	Adapter	1
	1U-8304	Fitting	1
	1P-4578	Half Flange	2
	8C-9024	Fitting As	1
	6V-3965	Fitting	1
	4J-0522	O-Ring Seal	1
	7M-8485	O-Ring Seal	1
	0T-0768	Bolt	4
	5P-8244	Hard Washer	4
E	9U-7446	Adapter	1
	1U-8301	Fitting	1
	6V-3965	Fitting	1
	8T-4184	Bolt	4
	8T-4223	Hard Washer	4
	1P-4579	Half Flange	2
	8C-9024	Fitting As	1
	4J-0524	O-Ring Seal	1
F	120-6843	Ball Valve	1
	8C-9024	Fitting As	1
	8C-9025	Quick Coupler	1
	3B-7749	Pipe Nipple	1
G	3B-6552	Pipe Elbow	1
	3B-7282	Pipe Nipple	1
	6V-4142	Fitting	1
H	6V-3966	Fitting As	1
	8J-7844	Adapter Fitting	1
	3K-0360	O-Ring Seal	1
J	4C-6818	Pressure Sensor Gp	11
K	4C-4897	Cover	1
L	1U-9482	Test Cable As	1
M	277-2362	Transmission Analyzer III Gp	1
N	4C-9910	Portable Hydraulic Tester	2
P	8T-0855	Pressure Gauge (0 - 4000 kPa (0 - 580 psi))	9
	6V-4144	Quick Connect Coupler	9
Q	8T-0854	Pressure Gauge ( 0 - 965 kPa (0 - 140 psi))	2
	6V-4144	Quick Connect Coupler	2

Installation Procedure

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Illustration 2	g01664819

1. Use proper lifting devices to set the transmission on the test bench. The weight of the transmission is 1134 kg (2500 lb).

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Illustration 3	g01665837

2. Use Tooling (A) to secure the transmission to the test bench during testing.

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Illustration 4	g01664875

3. Install Tooling (B) to the input yoke.

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Illustration 5	g01664893

4. Install Tooling (C) to Tooling (B) .

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Illustration 6	g01664915

5. Connect the drive shaft to Tooling (C) .

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Illustration 7	g01664933

6. Install the drive shaft guard.

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Illustration 8	g01664955

7. Remove drain plug (1) .

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Illustration 9	g01664973

8. Remove the cover plate and filter (2) from the transmission.

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Illustration 10	g01665034

9. Remove transmission cover (3) .

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Illustration 11	g01665053

10. Remove cover plate (4) .

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Illustration 12	g01665074

11. Remove cover plate (5) .

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Illustration 13	g01665077

12. Install Tooling (D) .

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Illustration 14	g01665093

13. Install Tooling (E) .

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Illustration 15	g01665135

14. Install Tooling (F) .

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Illustration 16	g01665113

15. Connect hose assembly (7) from the pressurized flow meter to Tooling (D) .

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Illustration 17	g01665154

16. Connect hose assembly (8) from Tooling (F) to the No. 2 flow meter.

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Illustration 18	g01665155

17. Connect hose assembly (9) from the outlet of the No. 2 flow meter to Tooling (E) .

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Illustration 19	g01665196

18. Remove plug (10) .

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Illustration 20	g01665209

19. Install Tooling (G) .

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Illustration 21	g01665854

20. Remove plug (11) .

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Illustration 22	g01665873

21. Install Tooling (H) .

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Illustration 23	g01665227
Main Pressure

22. Install Tooling (J) to Tooling (H) .

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Illustration 24	g01665216
(12) Pressure tap "A" for the No. 3 Clutch (13) Pressure tap "B" for the No. 1 Clutch (14) Pressure tap "C" for the No. 2 Clutch (15) Pressure tap "E" for the No. 5 Clutch (16) Pressure tap "F" for the No. 4 Clutch (17) Pressure tap "G" for the No. 6 Clutch (18) Pressure tap "H" for the No. 7 Clutch (19) Priority Reducing Valve Pressure

23. Install Tooling (K) .

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Illustration 25	g01665220

24. Install Tooling (J) .

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Illustration 26	g01665294
Torque Converter Relief Valve Pressure

25. Install Tooling (J) to Tooling (E) .

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Illustration 27	g01665295
Lubrication Pressure

26. Install Tooling (J) to Tooling (E) .

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Illustration 28	g01665296

27. Install Tooling (L) .

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Illustration 29	g01665298

28. Install Tooling (L) to a secure ground location.

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Illustration 30	g01457869
Tool (M)

29. Connect Tooling (M) to a power source. Refer to Tool Operating Manual, NEHS0996 for the correct operating instructions.

Test Procedure

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Personal injury or death can result from not following the proper procedures. To avoid the possibility of injury or death, follow the established procedure.

Harness Test

1. Make sure that Tooling (L) is properly connected.

2. Use Tooling (M) to perform the harness test.

3. Document if Harness Test passed or failed in Table 6.

Solenoid Test

1. Make sure that Tooling (L) is properly connected.

2. Use Tooling (M) to perform the harness test.

3. Record the values in Table 7.

Stall Speed Option

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NOTICE
If your transmission is equipped with a Stall Speed option, damage to the Test Bench and/or the transmission can occur when shifting from NEUTRAL to REVERSE. Ensure that the transmission is properly secured. Only check Stall Speed at 400 rpm.

1. Set input flow to 57 ± 4 L/min (15 ± 1 US gpm) at 0 rpm.

2. Shift the transmission from NEUTRAL to REVERSE.

3. If there are three clutches engaged, shift back to NEUTRAL. This indicates Stall Speed option on your transmission.

   1. Return to "Select Product" screen on Tooling (M) .

   2. Select "Generic ICM XMSN".

   3. Option 1: Select "7 Speed Stall ICM 24V" if you want to check Stall Speed.

   4. Option 2: Select "7 Speed Skip Stall 24V" if you do not want to check Stall Speed.

   5. Continue with test under one of the previous options.

4. If there are two clutches engaged, continue with test.

Start Checks

1. The preferred oil is SAE 10W oil viscosity grade. Warm oil to 50 °C (125 °F). If you are using Mobil DTE11 oil, warm the oil to 34 °C (95 °F). Maintain this temperature for the duration of the test.

2. Adjust the input flow to 57 ± 4 L/min (15 ± 1 US gpm).

3. Adjust input rotation to 0 rpm.

4. Shift the transmission through all gear ranges in order to ensure correct clutch engagement.

5. Refer to Table 4 for the correct clutch engagement.

6. Stop the input flow.

Table 4

Engagement Of Transmission Clutches
Transmission Speed	Engaged Clutches in the Transmission
NEUTRAL	1
REVERSE	3 and 7
FIRST speed	2 and 6
SECOND speed	1 and 6
THIRD speed	3 and 6
FOURTH speed	1 and 5
FIFTH speed	3 and 5
SIXTH speed	1 and 4
SEVENTH speed	3 and 4

Initial Pressure Check

1. Adjust the input flow to 57 ± 4 L/min (15 ± 1 US gpm).

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Illustration 31	g02720621

2. With the transmission in the NEUTRAL position, rotate the input shaft in a counterclockwise direction. Adjust the input rotation to 650 ± 30 rpm.

3. Shift the transmission through all speed ranges in order to eliminate air from the transmission controls.

4. Check for lockup or excessive drag in all ranges.

5. Stop the input rotation.

6. Stop the input flow.

7. Remove Tooling (K) .

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Illustration 32	g01630093

8. Remove the load piston plugs (24) from selector valve "A", "B", "C", "E", "F", "G"and "H".

9. Install Tooling (K) .

10. Adjust the input flow to 57 ± 4 L/min (15 ± 1 US gpm).

11. Adjust the input rotation to 650 ± 30 rpm.

12. Shift the transmission through each gear range.

    Note: Do not shift the transmission into REVERSE with the input rpm higher than 650 rpm.

13. Record the primary clutch pressure for each gear range in Table 9.

14. Record the pump pressure in Table 9.

15. Verify that the pump and primary clutch pressures match the values in Table 8.

16. Shift the transmission to the NEUTRAL position.

17. Stop the input rotation.

18. Stop the input flow.

19. Remove Tooling (K) .

20. Replace the load piston plugs.

21. Install Tooling (K) .

Priority Reducing Valve

1. Adjust the input flow to 57 ± 4 L (15 ± 1 US gal).

2. Adjust the input rotation to 650 ± 30 rpm in the NEUTRAL position.

3. Shift the transmission to the FORWARD 1 position.

4. The priority reducing valve pressure must be 1725 ± 70 kPa (250 ± 10 psi).

5. Record the value in Table 10.

Neutralizer Valve

1. Stop the input flow and the input rotation in a range that is not NEUTRAL.

2. Adjust the input flow to 57 ± 4 L/min (15 ± 1 US gpm).

3. Adjust the input rotation to 650 ± 30 rpm.

4. The neutralizer valve must prevent a pressure increase at any clutch station.

5. Record the values in Table 11.

6. Shift the transmission to the NEUTRAL position. The clutch pressure that is measured at pressure tap "B" must rise to a normal pressure.

7. Record the value in Table 12.

Lubrication Relief Valve

1. With the transmission in FIRST, adjust the input flow in order to produce a lubrication outlet flow of 38 ± 0.4 L/min (10 ± 0.1 US gpm).

2. Use Tooling (M) to block the flow at the torque converter inlet.

3. The lubrication outlet pressure must be 930 ± 100 kPa (135 ± 15 psi).

4. Record the value in Table 13.

5. Open Tooling (M) .

Lubrication Check

1. Adjust the input flow to 57 ± 4 L/min (15 ± 1 US gpm).

2. Adjust the input rotation to 650 ± 30 rpm.

3. With the transmission in the REVERSE and FORWARD 1, the lubrication pressure must be 27 ± 4 kPa (3.9 ± 0.6 psi).

4. Record the values in Table 14.

5. Adjust the input flow to 170 ± 4 L/min (45 ± 1 US gpm).

6. Adjust the input rotation to 2150 ± 30 rpm.

7. In all FORWARD and REVERSE ranges, the lubrication pressure must be 214 ± 28 kPa (31 ± 4 psi).

8. Record the values in Table 15.

Lubrication Circuit Check

1. Shift the transmission to FORWARD 2.

2. Adjust the input flow until the lubrication flow is 132.5 ± 0.4 L/min (35 ± 0.1 US gpm). Maintain this flow during this check.

3. Adjust the input rotation to 2150 ± 30 rpm.

4. The lubrication pressure must be 221 ± 17 kPa (32 ± 2.5 psi).

5. Record the value in Table 16.

Low Idle Pressure

1. Adjust the input flow to 57 ± 4 L/min (15 ± 1 US gpm).

2. Adjust the input rotation to 650 ± 30 rpm with the transmission in the NEUTRAL position.

3. Shift the transmission through each gear range.

   Note: Do not shift the transmission into REVERSE with the input rpm higher than 650 rpm.

4. Record the clutch pressures in Table 18.

5. Record the pump pressure in Table 18.

   Note: Pump pressure should be a minimum of 2516 kPa (365 psi).

6. Verify that the pump and clutch pressures match the values in Table 17.

7. Shift the transmission to the NEUTRAL position.

8. Stop the input rotation.

High Idle Check

1. Adjust the input flow to 170 ± 4 L/min (45 ± 1 US gpm).

2. Adjust the input rotation to 600 rpm.

3. Shift the transmission into FORWARD 1 position.

4. Adjust the input rotation to 2150 ± 30 rpm .

5. Record the clutch pressures in Table 20.

6. Record the pump pressure in Table 20.

   Note: Pump pressure should be a minimum of 3275 kPa (475 psi).

7. Verify that the pump and clutch pressures match the values in Table 19.

8. Repeat steps 2 through 7 for all gear ranges.

9. Shift the transmission to the NEUTRAL position.

10. Stop the input rotation.

Contamination Control

1. Take an oil sample of the test bench oil supply. Oil contamination must be maximum ISO 16/13.

2. Record the results in Table 21.

3. Remove the transmission from the test bench if the test bench oil supply is within specifications.

Transmission Bench Test Data Sheet

Table 5

CATERPILLAR	Transmission Bench Test Data Sheet	Test Date:
		Model: 69D, 768C, 769C, 769D, 771C, 771D
Work Order:		Serial No.:

Harness Test

Table 6

Harness Test
PASS	FAIL

Solenoid Test

Table 7

Solenoid Test	Upshift Solenoid	Downshift Solenoid
	_______ Ω	_______ Ω

Initial Pressure Check

Table 8

Initial Pressure Check
Gear Range	Engaged Clutches	Pump Pressure	Station (1) (2)
			"A"	"B"	"C"	"E"	"F"	"G"	"H"
			Pressure	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure
R	3 and 7	2515 kPa (365 psi) Min	520 kPa (75 psi)	-	-	-	-	-	345 kPa (50 psi)
N	1		-	345 kPa (50 psi)	-	-	-	-	-
1F	2 and 6		-	-	380 kPa (55 psi)	-	-	345 kPa (50 psi)	-
2F	1 and 6		-	345 kPa (50 psi)	-	-	-	345 kPa (50 psi)	-
3F	3 and 6		520 kPa (75 psi)	-	-	-	-	345 kPa (50 psi)	-
4F	1 and 5		-	345 kPa (50 psi)	-	380 kPa (55 psi)	-	-	-
5F	3 and 5		520 kPa (75 psi)	-	-	380 kPa (55 psi)	-	-	-
6F	1 and 4		-	345 kPa (50 psi)	-	-	380 kPa (55 psi)	-	-
7F	3 and 4		520 kPa (75 psi)	-	-	-	380 kPa (55 psi)	-	-

( 1 )	Station "D" is not used.
( 2 )	Refer to the Testing and Adjusting, "Transmission Hydraulic Control (Pressure Pack) - Test and Adjust" for the proper procedure to adjust the stations.

Table 9

Initial Pressure Check
Gear Range	Engaged Clutches	Pump Pressure	Station
			"A"	"B"	"C"	"E"	"F"	"G"	"H"
			Pressure	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure
R	3 and 7	2517 kPa (365 psi) Min for all ranges
N	1
1F	2 and 6
2F	1 and 6
3F	3 and 6
4F	1 and 5
5F	3 and 5
6F	1 and 4
7F	3 and 4

Priority Reducing Valve

Table 10

Priority Reducing Valve Pressure

Input Speed (650 ± 30 rpm) in NEUTRAL Input Flow 57 ± 4 L/min (15 ± 1 US gpm) Gear Range FORWARD 1

kPa (psi)

Neutralizer Valve

Table 11

Neutralizer Valve (Step 1)			Input Speed (650 ± 30 rpm) Input Flow 57 ± 4 L/min (15 ± 1 US gpm) Any Gear Range Except NEUTRAL
A	B	C	D	E	F	G	H
kPa (psi)	kPa (psi)	kPa (psi)	kPa (psi)	kPa (psi)	kPa (psi)	kPa (psi)	kPa (psi)

Table 12

Neutralizer Valve (Step 2)		Gear Range NEUTRAL
Station "B"		kPa (psi)	The clutch pressure must rise to normal pressure.		Yes	No

Lubrication Relief Valve Check

Table 13

Lubrication Outlet Pressure

Input Speed (650 ± 30 rpm)

kPa (psi)

Lubrication Check

Table 14

Lubrication Check	Input Speed (650 ± 30 rpm) Input Flow 57 ± 4 L/min (15 ± 1 US gpm)
Gear Range	Lubrication Pressure		Lubrication Flow
R	kPa (psi)		kPa (psi)
1F	kPa (psi)		kPa (psi)

Table 15

Lubrication Check	Input Speed (2150 ± 30 rpm) Input Flow 170 ± 4 L/min (45 ± 1 US gpm)
Gear Range	Lubrication Pressure		Lubrication Flow
R	kPa (psi)		kPa (psi)
1F	kPa (psi)		kPa (psi)
2F	kPa (psi)		kPa (psi)
3F	kPa (psi)		kPa (psi)
4F	kPa (psi)		kPa (psi)
5F	kPa (psi)		kPa (psi)
6F	kPa (psi)		kPa (psi)
7F	kPa (psi)		kPa (psi)

Lubrication Circuit Check

Table 16

Lubrication Pressure

Gear Range FORWARD 2 Input Speed (2150 ± 30 rpm) Input flow 132 L/min (35 US gpm)

kPa (psi)

Low Idle Pressure Check

Table 17

Clutch Pressures At Low Idle
Gear Range	Engaged Clutches 4	Station (1) (2)
		"A"	"B"	"C"	"E"	"F"	"G"	"H"
		Pressure	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure
R	3 and 7	1700 kPa (247 psi)	-	-	-	-	-	2760 kPa (400 psi)
N	1	-	2035 kPa (295 psi)	-	-	-	-	-
1F	2 and 6	-	-	1885 kPa (273 psi)	-	-	2760 kPa (400 psi)	-
Stall	1, 2, and 3	1700 kPa (247 psi)	2035 kPa (295 psi)	1885 kPa (273 psi)

( 1 )	Station "D" is not used.
( 2 )	Refer to the Power Train Testing and Adjusting, "Transmission Hydraulic Control (Pressure Pack) - Test and Adjust" for the proper procedure to adjust the Stations.

Table 18

Clutch Pressures At Low Idle
Gear Range	Engaged Clutches 4	Pump Pressure	Station
			"A"	"B"	"C"	"E"	"F"	"G"	"H"
			Pressure	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure
R	3 and 7	2517 kPa (365 psi) Min for all ranges
N	1
1F	2 and 6
Stall	1, 2, and 3

High Idle Pressure Check

Table 19

Clutch Pressures At High Idle
Gear Range	Engaged Clutches	Station (1) (2)
		"A"	"B"	"C"	"E"	"F"	"G"	"H"
		Pressure	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure
R	3 and 7	1700 kPa (247 psi)	-	-	-	-	-	2930 kPa (425 psi)
N	1	-	2035 kPa (295 psi)	-	-	-	-	-
1F	2 and 6	-	-	1885 kPa (273 psi)	-	-	2930 kPa (425 psi)	-
2F	1 and 6	-	2035 kPa (295 psi)	-	-	-	2930 kPa (425 psi)	-
3F	3 and 6	1700 kPa (247 psi)	-	-	-	-	2930 kPa (425 psi)	-
4F	1 and 5	-	2035 kPa (295 psi)	-	2015 kPa (292 psi)	-	-	-
5F	3 and 5	1700 kPa (247 psi)	-	-	2015 kPa (292 psi)	-	-	-
6F	1 and 4	-	2035 kPa (295 psi)	-	-	1430 kPa (207 psi)	-	-
7F	3 and 4	1700 kPa (247 psi)	-	-	-	1430 kPa (207 psi)	-	-

( 1 )	Station "D" is not used.
( 2 )	Refer to the Testing and Adjusting, "Transmission Hydraulic Control (Pressure Pack) - Test and Adjust" for the proper procedure to adjust the stations.

Table 20

Clutch Pressures At High Idle
Gear Range	Engaged Clutches	Pump Pressure	Station
			"A"	"B"	"C"	"E"	"F"	"G"	"H"
			Pressure	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure
R	3 and 7	3275 kPa (475 psi) Max pressure for all ranges
N	1
1F	2 and 6
2F	1 and 6
3F	3 and 6
4F	1 and 5
5F	3 and 5
6F	1 and 4
7F	3 and 4

Contamination Control

Table 21

ISO Particle Count

Sample the test bench oil supply.

________/________Particle Count

Table 22

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