Procedure for Filtering Off-Highway Truck Rear Axle Oil {0680, 0768, 3260, 4050} Caterpillar

Off-Highway Truck/Tractor

785 (S/N: 8GB1-UP)

785B (S/N: 6HK1-UP)

785C (S/N: 1HW1-UP; APX1-UP; 5AZ1-UP)

785G (S/N: RTL1-UP)

789 (S/N: 9ZC1-UP)

789B (S/N: 7EK1-UP)

789C (S/N: 2BW1-UP)

789D (S/N: SPD1-UP; SHH1-UP)

793 (S/N: 3SJ1-UP)

793B (S/N: 1HL1-UP)

793C (S/N: 4AR1-UP; ATY1-UP; 4GZ1-UP)

793D (S/N: FDB1-UP)

793F (S/N: SND1-UP; SSP1-UP; D3T1-UP; RBT1-UP)

797 (S/N: 5YW1-UP)

797B (S/N: JSM1-UP)

797F (S/N: LAJ1-UP; WSP1-UP)

Introduction

© 2018 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 guideline enables dealers and customers to benefit from cost reductions which were made possible through an established contamination control program. Fluids that are used in Caterpillar machines are highly effective unless the fluid contains high amounts of contaminates. Every effort must be made to reduce the contamination level within Caterpillar fluid systems. Caterpillar makes ongoing changes and improvements to the Caterpillar products. This guideline must be used with the latest technical information available from Caterpillar. The latest technical information will ensure that such changes and improvements are incorporated when applicable.

For technical questions when using this document, work with your Dealer Technical Communicator (TC).

To report suspected errors, inaccuracies, or suggestions regarding the document, submit a form for feedback in the Service Information System (SIS Web) Interface.

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Canceled Part Numbers and Replaced Part Numbers

This document may 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.

Summary

The instructions that are given in this guideline will enable dealers and the dealers customers to properly filter Off-Highway Truck axle oil. Following this procedure will reduce contamination in the oil to an acceptable ISO contamination level. This procedure may be modified by the technician for use on some machines.

Important Safety Information

Illustration 1	g02139237

Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly.

Improper operation, lubrication, maintenance, or repair of this product is dangerous. Improper methods could result in injury or death.

Do not operate or perform any lubrication, maintenance, or repair of this product, until you understand the operation, lubrication, maintenance, and repair information. Safety precautions and warnings are provided in this guideline and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.

Hazards are identified by a safety alert symbol. Safety alert symbols are followed by a signal word such as "Warning" that is shown below.

Illustration 2	g01032906

The following is the meaning of this safety alert symbol:

• Pay attention!

• Become alert!

• Your safety is involved.

The message that appears under the warning explains the hazard. The message will be written or pictorially shown.

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. Therefore, the warnings in this publication and on the product are not all inclusive. If a tool, a procedure, a work method, or an operating technique that is not recommended by Caterpillar is used, ensure that the procedure is safe for all personnel around the machine. Ensure that the product will not be damaged or that the product will not be made unsafe by the operation, lubrication, maintenance, or repair procedures.

All the information, specifications, and illustrations that are in this publication are based on information that was available at the time of publication. The following information could change at any time: specifications, torque, pressures, measurement, adjustments, illustrations, and other items. These changes can affect the service that is given to the product. Obtain the most current and complete information before you start any job. Caterpillar dealers have the most current information that is available.

Safety

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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the steering system.

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

References

Tooling and Equipment

Off-Highway Truck Rear Axle Oil Filter Cart Procedure

Note: The following procedure is not to be used for Electric Drive trucks.

The following procedure is intended for the 785 through 797 Off-Highway Truck models. The procedure is most effective when performed immediately after the rear axle oil has been warmed to 50 °C (122 °F) and mixed from operation. Warming of the oil allows any contamination in the system oil to be placed in suspension and also lowers the viscosity. Be sure to read and understand the Tool Operating Manual, NEHS0779, "183-9301 Heavy Weight Filter Cart" before you begin the procedure.

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Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact skin. At operating temperature, the engine coolant is hot and under pressure. Steam can cause personal injury. Check the coolant level only after the engine has been stopped and the cooling system pressure cap is cool enough to touch with your bare hand. Remove the cooling system pressure cap slowly to relieve pressure. Cooling system conditioner contains alkali. Avoid contact with the skin and eyes to prevent personal injury.

1. Park the machine on level ground. Engage the parking brake.
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   Illustration 3	g01284651
   (1) Air breather

2. Remove the air breather (1) on top of the rear axle housing.
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   Illustration 4	g01284653
   (2) 5P-0306 Vacuum Transducer (3) Air supply hose

3. Install the 5P-0306 Vacuum Transducer (2) in place of the air breather on top of the rear axle housing. Connect an air supply hose (3) to the transducer.

4. Operate the vacuum transducer before removing the final drive plugs and before removing the rear axle differential housing drain plug.

   Note: Be sure that the rear axle oil system has pulled a vacuum. The hot oil could cause injury if a vacuum is not accomplished.

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   Illustration 5	g01284654
   (4) Final drive magnetic plug

5. Remove one final drive magnetic plug (4).
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   Illustration 6	g01284658
   (5) Final drive adapter (6) 195-5924 Return Adapter (7) Filter cart return hose

6. Quickly install the proper final drive adapter (5). Be sure to inspect the magnetic plug for contaminants.

7. Repeat Steps 4 and 5 for the opposite final drive.

8. Install the 195-5924 Return Adapter (6) to the left and to the right final drive adapters. Be sure that the return adapter valve is in the closed position. Refer to Illustration 6.

9. Connect the filter cart return hoses (7) to the left and right return adapters.
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   Illustration 7	g01284659
   (8) Differential adapter (9) 196-2114 Suction Adapter (10) Filter cart suction hose

10. Remove the differential case drain plug and quickly install the proper differential adapter (8).

11. Install the 196-2114 Suction Adapter (9) to the differential adapter. Be sure that the suction adapter valve is in the CLOSED position.

12. Connect the filter cart suction hose (10) to the suction adapter.

13. Disconnect the air supply from the vacuum transducer to relieve the rear housing vacuum.

    Note: Leave the vacuum transducer connected to the rear axle to complete the filter cart removal procedure later in this guideline.

14. Open both return adapter valves. Open the suction adapter valve.

15. Ensure that there are no oil leaks from any of the filter cart connections or adapters.

    Note: This filter cart connection configuration will flush contaminants toward the center differential housing and away from the final drive bearings. The filter cart will remove any contaminants from the lower differential case.

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    Illustration 8	g01284662
    (11) Air supply hose (12) Air supply valve

16. Attach an air supply hose (11) to the 245-1769 Filter Cart. Ensure that the air supply valve (12) is in the CLOSED position. Be sure that the air supply does not exceed 690 kPa (100 psi).
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    Illustration 9	g01284663
    (13) Filter manual bypass valve (open)

17. Move the filter manual bypass valve (13) to the OPEN position. Opening the valve will eliminate initial high-pressure oil flow surges in the filter. Opening the valve will also purge all air from the filter cart plumbing and the filter cart hoses.
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    Illustration 10	g01284665
    Air supply valve

18. Slowly open the air supply valve (12) to start the filter cart pump operation. The pump is a double acting diaphragm pump. The pump is rated to pump 50W to 60W oil at approximately 208 L/min (55 US gpm).
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    Illustration 11	g01284669
    (13) Filter manual bypass valve (closed)

19. Close the filter manual bypass valve (13) after the pump has started to pump oil and the hoses and the filter are full of oil. Closing the manual bypass valve will close the bypass and divert the full pump oil flow through the filter.
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    Illustration 12	g01284670
    (12) Air supply valve (open)

20. When the filter manual bypass is fully CLOSED, slowly open the air supply valve (12) to the OPEN position.

    Note: Caterpillar recommends that a particle count is to be taken on the oil at the beginning of the filter cycle as a baseline particle count.

21. The oil can be particle count tested for cleanliness in one of the two following ways.

    • Use a 170-8500 Portable Particle Analyzer for immediate results.

    • Collect a bottle sample and send the sample to an S·O·S lab.

22. When using the 170-8500 Portable Particle Analyzer for particle counting, be sure to read and understand the Tool Operating Manual, NEHS0799, "S40 Portable Particle Analyzer" before you operate the particle analyzer.
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    Illustration 13	g01284672
    (11) S·O·S valve (16) Automatic bypass valve

23. Connect the "low pressure in" port to the S·O·S valve (14) on the filter cart.

24. If collecting a bottle sample, use the sample S·O·S valve (14) and a 169-8373 Fluid Sampling Bottle.

25. Record an oil sample reading from the S·O·S valve (14) on the filter cart at the beginning of the filter cycle.

26. Operate the filter cart (14) until the portable particle analyzer indicates that the oil has reached an ISO level of at least 18/15. The final ISO code should be recorded before the machine is returned to the field.

    Note: Refer to "Oil Compartment Filtration Times" at the end of this document when a 170-8500 Portable Particle Analyzer is not available. Oil Compartment Filtration Times will determine a recommended length of time for the filtration process.

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    Illustration 14	g01284673
    (15) Filter restriction gauge

27. The restriction gauge (15) will indicate when the filter needs to be changed. The restriction gauge is at the top of the filter housing. The filter element is clean when a white background exists in the sight glass. As the element gets dirty, the background will shift downward to expose the dark gray color of the inner filter housing.

    Note: Oil might be present behind the sight gauge. This oil has no bearing on the cleanliness of the element.

28. The filter cart is equipped with an automatic dirty element bypass valve (16) as shown in Illustration 13. Oil will bypass the filter element when this valve opens.

    Note: The filter restriction gauge (15) will display a dirty element before the automatic bypass valve (16) opens.

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    Illustration 15	g01284676
    (11) Air supply hose (12) Air supply valve (CLOSED)

29. When the target ISO level or the time interval has been met, close the air supply valve (12). Disconnect the air supply hose (11).
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    Hot oil and components can cause personal injury. Do not allow hot oil or components to contact skin.

30. Close both of the return adapter valves (6). Close the suction adapter valve. Refer to Illustrations 6 and 7.

    Note: Leave the return adapters (6) permanently connected to the filter cart return hoses (7). Also leave the suction adapter (9) permanently connected to the filter cart suction hose (10). These permanent connections will aid in the future use and the connections help prevent hose contamination.

31. Disconnect all filter cart oil hoses from the Off-Highway Truck.
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    Illustration 16	g01284675
    (2) 5P-0306 Transducer (3) Air supply hose

32. Reinstall the air supply hose (3) to the 5P-0306 Transducer (2).

33. Operate the vacuum transducer prior to installing the final drive plugs and the differential case drain plug.

    Note: Be sure that the rear axle oil system has pulled a vacuum before continuing.

34. Remove the final drive adapters (5). Remove the differential adapter (8). Quickly install all plugs. Refer to Illustrations 6 and 7.
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    Illustration 17	g01284679
    (1) Air breather

35. Remove the vacuum transducer. Reinstall the air breather (1).

36. Check and maintain the oil level in the differential and final drives to the recommended oil levels according to the Operation and Maintenance Manual.

37. Reinstall the protective caps on the filter cart hoses to control contamination.

Oil Compartment Times for 245-1769 Filter Cart

If an on-line portable particle counter is not available to diagnose and track when the contaminant level has lowered to an acceptable level, refer to the following equation. This equation relates to the 245-1769 Filter Cart only. Other filtration units will use different equation references. The units that use different equations will be noted when appropriate.

Illustration 18	g01284927
(A) Compartment Oil Capacity (gal) (B) Pulses per Minute (C) Approximate Filtration Time (min)

Pulses Per Minute Definition

Each air discharge or each stroke of the air operated filter pump delivers one pulse of oil. The internal pump shaft will slide left (one pulse), and then to the right (one pulse). Each pulse of the pump delivers oil in both directions. Another way of determining pulses is to listen for the sound of two separate pulses. Count the number of pulses in 1 minute for use in the above equation.

Example

A 793C Off-Highway Truck rear axle has 776 L (205 US gal) of SAE 60W oil. The filter cart is operating at 78 pulses per minute. The approximate filtration time should be 89 minutes or an hour and a half.

ISO 4406:1999 Method for Coding the Level of Contaminates by Solid Particles

ISO is a worldwide federation of national standards bodies. The ISO 4406:1999 specifies the code to be used in defining the quantity of solid particles in the fluid. This ISO code is used in any given hydraulic fluid power system. An automatic particle counter derives the equivalent size of a particle from the cross sectional area of the particle. Particle counts are affected by various factors. These factors include the procurement of the sample, the sample container, particle counting accuracy where used and the particle count cleanliness. Proper care should be taken during the sample procurement process. Proper care will ensure that the sample obtained is representative of the fluid circulating in the system.

The code for contamination levels using automatic particle counters is composed of three scale numbers. Example X/Y/Z.

X - The number of particles that is equal to or larger than 4 microns.

Y - The number of particles that is equal to or larger than 6 microns.

Z - The number of particles that is equal to or larger than 14 microns

Currently Caterpillar does not require the reporting of the "X" scale number since the hydraulic tolerances exceed the 4 micron value. Therefore a (-) is used in place of the 4 micron value. For example, a particle count is read as -/Y/Z, meaning that there was no requirement to count particles equal to or larger than 4 microns.