Bench Test Procedure for a 988G and 988H Wheel Loader Transmission {3030, 3073, 3139} Caterpillar

Wheel Loader

988G (S/N: BNH1-UP; 2TW1-UP)

988H (S/N: A7A1-UP; BXY1-UP)

Introduction

Table 1

Revision	Summary of Changes in REHS1670
05	Standardized.
04	Updated Introduction. Updated Tooling in Table 3. Standardized.
03	Added A7A serial number prefix and new introduction.

© 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 a specific transmission arrangement. 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. Testing 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 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. To address an urgent issue, use the following resources to communicate your request to Caterpillar Repair Process Engineering:

• Caterpillar Dealer Technical Communicator

• Dealer Solution Network

• Caterpillar Technical Representative

• Knowledge Network

Table 2

Machine Model	Transmission Arrangement
988G	187-8133, 192-2914
988H	230-6315

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.

Important Safety Information

Illustration 1	g02139237

Follow all safety warnings. Most accidents that involve product operation, maintenance, or repair are caused by failure to observe safety warnings. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. Personnel must be properly trained to perform maintenance, repair, or operate any machine. Safety precautions and warnings are provided this instruction and on Caterpillar products. These warnings should be observed before performing any procedures. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are not all inclusive.

The hazards are identified by the “Safety Alert Symbol” which is followed by a “Signal Word” such as “DANGER”, “WARNING, or” “CAUTION”. The “WARNING” Safety Alert Symbol is shown in illustration below.

Illustration 2	g00008666

This safety alert symbol means:

Pay Attention!

Become Alert!

Your Safety is Involved.

The message that appears under the safety alert symbol explains the hazard.

Operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The safety information in this document and the safety information on the machine are not all inclusive. Determine that the tools, procedures, work methods, and operating techniques are safe. Determine that the operation, lubrication, maintenance, and repair procedures will not damage the machine. Also, determine that the operation, lubrication, maintenance, and repair procedures will not make the machine unsafe.

The information, the specifications, and the illustrations that exist in this guideline are based on information which was available at the time of publication. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete, most current information before you start any job. Caterpillar dealers can supply the most current information.

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 often used to compare values on portions of transmission tests. 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.

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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 to develop this test procedure.

Table 3

Required Tools
Tool	Part Number	Part Description	Qty
A	1U-9584	Rail As	2
	4C-9998	Bracket As	2
	159-0747	Crossmember	1
	6V-3669	Bolt (20-2.00X80 mm)	4
	8T-3282	Hard Washer	4
	1D-4590	Bolt	4
	5P-8247	Hard Washer	8
	4K-0367	Full Nut	4
B	241-0070	Drive Adapter	1
	6V-3668	Bolt (12-1.75X30 mm)	4
	3B-4508	Lockwasher	4
C	1U-9722	Load Binder As (Ratchet Type)	4
	439-3939	Link Bracket As	4
	1A-8063	Bolt (3/4-10X2.5 inch)	2
	5P-8248	Hard Washer	4
	6V-5686	Bolt	2
	5P-8247	Hard Washer	2
D	9U-7445	Adapter	1
E	1U-8301	Fitting	2
	9U-7445	Adapter	2
	197-3295	Half Flange	4
	8C-9024	Fitting As (Plain)	2
	6V-3965	Fitting As (Quick Disconnect)	2
	3J-1907	O-Ring Seal	2
	6V-8675	Bolt (M12-1.75X35 mm)	8
	5P-8245	Hard Washer	8
F	1U-8304	Fitting	1
	9U-7445	Adapter	1
	197-3295	Half Flange	2
	8C-9024	Fitting As (Plain)	1
	6V-3965	Fitting As (Quick Disconnect)	1
	3J-1907	O-Ring Seal	1
	6V-8675	Bolt (M12-1.75X35 mm)	4
	5P-8245	Hard Washer	4
G	120-6843	Ball Valve	1
	8C-9024	Fitting As	1
	8C-9025	Quick Coupler	1
H	6V-3965	Fitting As (Quick Disconnect)	1
	3J-1907	O-Ring Seal	1
J	8T-0855	Pressure Gauge (0 to 4,000 kPa (0 to 580 psi))	2
	6V-4144	Coupler	2
K	8T-0863	Pressure Gauge (0 to 250 kPa (0 to 36 psi))	2
	6V-4144	Coupler	2
L	9U-7500	Transmission Analyzer Tool Gp	1
	OR
	277-2362	Transmission Analyzer III Gp	1
M(1)	306-0397	Extension Cable (Transmission Analyzer)	1
	459-4084	Adapter Cable As	1
N(2)	FT-3187	Adapter Harness As	1
	306-0397	Extension Cable	1
P	146-4080	Digital Multimeter	1
	5P-5677	Electrical Wire	1
	155-2270	Connecting Plug Kit	1
	186-3736	Connector Socket	2

(1)	Use if testing 988G
(2)	Use if testing 988H

FT Drawings

Illustration 3	g03796356
FT-3187

Table 4

FT-3187
Callout	Part Number	Description	Qty
(A)	3E-5179	Connector Receptacle As	1
(B)	9X-1339	Connector Receptacle As	1
(C)	3E-3382	Connector Receptacle As	1
	8T-8729	Connector Pins	27

Use 3 DM long 18 AWG stranded copper wire for most connections.

Use 50 mm (2.0 inch) to 100 mm (4 inch) wire for jumper/slice connection.

Installation Procedure

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Illustration 4	g03798492

1. Install Tooling (A) to the test bench.
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   Illustration 5	g01014252

2. Use a hoist to install the transmission on the test bench. The weight of the transmission is 1504 kg (3315 lb).
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   Illustration 6	g01014255

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

   Note: Use the small drive shaft with this tool.

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   Illustration 7	g01014256

4. Using the hoist and pry bars, slide the transmission forward to align with the input drive shaft.

5. Connect the input drive shaft to Tooling (B).
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   Illustration 8	g01014257

6. Install the drive shaft guard.
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   Illustration 9	g03802221

7. Tighten all four castle nuts and jack bolts.
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   Illustration 10	g01014258

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   Illustration 11	g06014324

8. Install Tooling (C) to the output end of the transmission.
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   Illustration 12	g01014260

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   Illustration 13	g01014261

9. Install Tooling (C) to the input end of the transmission.
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   Illustration 14	g01014262

10. Remove cover plate (1).
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    Illustration 15	g01014265

11. Remove filter assembly (2).
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    Illustration 16	g01014266

12. Remove drain plug (3).
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    Illustration 17	g01014267

13. Install Tooling (D).

    Note: Tooling (D) will activate the drain valve allowing the oil to drain into the test bench.

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    Illustration 18	g01014268
    Left - Controls (in)/Supply Oil Right - Controls (out)

14. Install Tooling (E).
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    Illustration 19	g01014270
    Lube (in)

15. Install Tooling (F).
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    Illustration 20	g03806227
    Lube (in)

16. Install Tooling (G) onto Tooling (F).
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    Illustration 21	g03806283
    Lube Pressure

17. Install Tooling (H).
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    Illustration 22	g01014272
    (4) Controls (in)/Supply Oil

18. Connect hose assembly (4) from the pressurized flow meter to Tooling (E).

    Note: The flow meter will measure the flow of the supply oil.

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    Illustration 23	g01014273
    (5) Controls (out)

19. Connect hose assembly (5) from Tooling (E) to the No. 2 flow meter inlet.
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    Illustration 24	g03806299
    (6) Lube (in)

20. Connect hose assembly (6) from the No. 2 flow meter outlet to Tooling (G).
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    Illustration 25	g01014276
    Transmission Control Supply Pressure

    Note: If you are using individual pressure gauges to measure the pressures, refer to Table 3 for the correct pressure gauges.

21. Connect a pressure gauge to pressure tap (7).
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    Illustration 26	g01014277
    Controls (out) Pressure

22. Connect a pressure gauge to pressure tap (8).
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    Illustration 27	g01014278
    Lube Pressure

23. Connect a pressure gauge to pressure tap (9).
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    Illustration 28	g03806327

24. Connect Tooling (M) to the transmission.
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    Illustration 29	g03806347

25. Connect Tooling (M) to a suitable location.
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    Illustration 30	g01014281

26. Cover the transmission. Use a suitable clean cover.
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    Illustration 31	g00877510
    Tooling (L)

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    Illustration 32	g01457869
    Tooling (L)

27. Connect Tooling (L) to a power source. Refer to Tool Operating Manual, NEHS0644 for the correct operating instructions for 9U-7500 Transmission Analyzer Tool Gp.

    OR

    Connect Tooling (L) to a power source. Refer to Tool Operating Manual, NEHS0996 for the correct operating instructions for 277-2362 Transmission Analyzer III Gp.

Test Procedure

TA3 Navigation

1. Select “Wheel Loaders”.

2. Select “988H - 24V” or “988G - 24V”.

Solenoid Test (TA2 only)

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

2. Use Tooling (L) to perform the solenoid test.

3. Record the values in Table 7.

   Note: Do not continue testing until Solenoid Test passes.

Harness Test (TA3 only)

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

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

3. Record the values in Table 7.

   Note: Do not continue testing until Harness Test passes.

Start Checks

Note: Refer to Testing and Adjusting, RENR3095, "988G Wheel Loader Power Train" for the correct adjusting procedures.

1. If you are using SAE 10W oil, warm the 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 67 ± 1 L/min (17 ± 1 US gpm).
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   Illustration 33	g02720621

3. With the transmission in the NEUTRAL position, rotate the input shaft in a counterclockwise direction. Adjust the input rotation to 750 ± 35 rpm.

4. The lubrication pressure must be between minimum 7 kPa (1 psi).

   Note: If there is no lube pressure after 3 seconds, stop input rotation and check connections on test bench and transmission.

5. Record the value in Table 8.

6. Shift the transmission through all gears to eliminate air from the transmission controls.

7. Confirm clutch engagement with Table 5.
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   Table 5

   Clutch Engagement Check
   Gear	Cl 1	Cl 2	Cl 3	Cl 4	Cl 5	Cl 6
   N			X
   F1		X				X
   F2		X			X
   F3		X		X
   F4		X	X
   R1	X					X
   R2	X				X
   R3	X			X
   R4	X		X

8. Stop the input rotation.

9. Stop the input flow.

Torque Converter Relief Valve Check

1. Adjust the input flow to 67 ± 1 L/min (17 ± 1 US gpm). Maintain this flow during this check.

2. With the transmission in the NEUTRAL position, rotate the input shaft in a counterclockwise direction. Adjust the input rotation to 750 ± 35 rpm.

3. Shift the transmission to FORWARD 1.

4. Use Tooling (G) to momentarily block the lube flow.

5. The torque converter inlet pressure must be 980 ± 55 kPa (142 ± 8 psi).

6. Open Tooling (G).

7. Record the value in Table 9.

Lube Circuit Check

1. Adjust the input flow until the lube flow is 153 ± 1 L/min (40 ± 1 US gpm). Maintain this flow during this check.

2. Adjust the input rotation to 700 ± 35 rpm.

3. Shift the transmission to FORWARD 3.

4. Adjust the input rotation to 1900 ± 35 rpm.

5. The lubrication pressure must be 152 ± 14 kPa (22 ± 2 psi).

6. Record the value in Table 10.

Clutch Leakage Check

1. Adjust the supply flow to 167 ± 1 L/min (44 ± 1 US gpm). Maintain this flow during this check.

2. The supply pressure should be 2895 ± 138 kPa (420 ± 20 psi).

3. Adjust the input rotation to 750 ± 35 rpm.

4. Shift the transmission to the FORWARD 1 position.

5. Adjust the input rotation to 1900 ± 35 rpm.

6. Record the input flow in Table 11.

7. Record the lube flow in Table 11.

8. The leakage is obtained by subtracting the lube flow from the input flow.

9. Record the calculation in Table 11.

10. Adjust the input rotation to 750 ± 35 rpm.

11. Shift the transmission through positions FORWARD 2, FORWARD 3, FORWARD 4. Return back to NEUTRAL and shift through positions REVERSE 1, REVERSE 2, REVERSE 3, and REVERSE 4. Repeat Steps 5 through 10 for each gear range.

    Note: Always return to NEUTRAL when shifting between FORWARD and REVERSE.

12. The leakage for FIRST, THIRD, and FOURTH gear ranges in FORWARD and REVERSE should be 28.4 ± 3.8 L/min (7.5 ± 1 US gpm).

13. The leakage for SECOND gear range in FORWARD and REVERSE should be 32.6 ± 4.5 L/min (8.6 ± 1.2 US gpm).

14. The difference in leakage between the FIRST, THIRD, and FOURTH gear ranges or between FORWARD and REVERSE shall be no more than 2.3 L/min (0.6 US gpm).

15. The leakage between SECOND and FIRST, THIRD, and FOURTH shall be no more than 4.5 ± 3 L/min (1.2 ± 0.8 US gpm).

16. Record the calculations in Table 11.

17. Adjust the input rotation to 750 ± 35 rpm.

Speed Sensor Test

Note: There are two output speed sensors that must be identified and tested.

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Illustration 34	g06015402
Tooling (P)

1. Connect Tooling (P) to input speed sensor (25).

2. Adjust the input rotation to 965 ± 45 rpm.

3. Shift the transmission to FORWARD 2.

4. Adjust the input rotation until the frequency that is measured by Tooling (P) matches the value in Table 12.
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   Illustration 35	g01014336
   (10) Output Speed Sensor "No. 2" (11) Output Speed Sensor "No. 1"

5. Use Tooling (P) to measure the sensor signal voltage. Measure each speed sensor.

   Note: The voltage for each sensor must be equal to or greater than the values in Table 12.

6. Record the values in Table 13.

7. Verify the test points with the values in Table 12.

Transmission Bench Test Data Sheet

Table 6

CATERPILLAR	Transmission Bench Test Data Sheet	Test Date:______
		Model:______
Work Order:______		Serial No.:______

Solenoid Test/Harness Test

Table 7

Solenoid 1	Solenoid 2	Solenoid 3	Solenoid 4	Solenoid 5	Solenoid 6
_______ ohms	_______ ohms	_______ ohms	_______ ohms	_______ ohms	_______ ohms

Start Checks

Table 8

Lubrication Pressure
Input Speed (750 ± 35 rpm) Input Flow 67 ± 1 L/min (17 ± 1 US gpm)				7 kPa (1 psi)	______kPa ______(psi)

Torque Converter Inlet Pressure

Table 9

Torque Converter Inlet Pressure		Input Speed (750 ± 35 rpm) Input Flow 67 ± 1 L/min (17 ± 1 US gpm)
979 ± 55 kPa (142 ± 8 psi)		______kPa ______(psi)

Lube Circuit Check

Table 10

Lube Circuit Check		Gear Range FORWARD 3 Lube Flow 153 ± 1 L/min (40 ± 1 US gpm)
Nominal		152 ± 14 kPa (22 ± 2 psi)
Average Lubrication Pressure Of Arrangement	_______kPa ______(psi)	Lubrication Pressure	_______kPa ______(psi)

Clutch Leakage Check

Table 11

Clutch Leakage Check			Input Speed (1900 ± 35 rpm) Input Flow 167 ± 1 L/min (44 ± 1 US gpm)
Gear Range	N	F1	F2	F3	F4	R1	R2	R3	R4
Input Flow	______	______	______	______	______	______	______	______	______
Lube Flow	______	______	______	______	______	______	______	______	______
Leakage	______	______	______	______	______	______	______	______	______
Averages		1F+3F+4F/3=_____________				1R+3R+4R/3=_____________

Speed Sensor Test

Table 12

Sensor	Frequency (Hz)	Minimum Volts (Vrms)
Output Speed Sensor 1	130	4.2
Output Speed Sensor 2	130	4.2

Table 13

Speed Sensor Test	Input Speed (700 ± 5 rpm) Gear Range FORWARD 2
Output Speed Sensor 1	__________________ Frequency (Hz)	__________________ Volts/Vpp
Output Speed Sensor 2	__________________ Frequency (Hz)	__________________ Volts/Vpp

Contamination Control

Table 14

ISO Particle Count

Sample the test bench oil supply. *ISO 4406 is 16/13 or better

________/________Particle Count

Table 15

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______________________________________ Supervisor