193-4124 Rear Wheel Bearing Preload Adjuster for 793 Off-Highway Trucks{0374, 0599, 0700, 0722, 0727, 0731} Caterpillar

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Introduction

Important Safety Information

Illustration 1	g02139237
Think Safety

European Union Compliant, CE Marked

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 can be dangerous and could result in injury or death.

Do not operate or perform any lubrication, maintenance, or repair on this product until you have read and understood the Tool Operating Manual.

Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.

The hazards are identified by the "Safety Alert Symbol" and followed by a "Signal Word" such as "DANGER", "WARNING", or "CAUTION". The Safety Alert "WARNING" label is shown below.

A non-exhaustive list of 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 warnings in this publication and on the product are, therefore, not all inclusive. If a tool, procedure, work method, or operating technique that is not recommended by Caterpillar is used, the operator must be sure that the procedures are safe. The operator must also be sure that the product will not be damaged or made unsafe by any unspecified procedures.

The information, specifications, and illustrations in this publication are based on information that was available at the time that the publication was written. 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 and most current information before you start any job.

When replacement parts are required for this product Caterpillar recommends using Caterpillar replacement parts or parts with equivalent specifications including, but not limited to, physical dimensions, type, strength, and material.

Literature Information

This manual contains safety information, operation instructions and maintenance information and should be stored with the tool group

Some photographs or illustrations in this publication may show details that can be different from your service tool. Guards and covers might have been removed for illustrative purposes.

Continuing improvement and advancement of product design might have caused changes to your service tool, which are not included in this publication.

Whenever a question arises regarding your service tool or this publication, consult Dealer Service Tools (DST) for the latest available information.

Safety Section

The Safety section lists basic safety precautions.

Read and understand the basic precautions listed in the Safety section before operating or performing maintenance and repair on this service tool.

General Information Section

The General Information section describes tooling functions and features. The section provides useful information on individual parts, additional tooling, and resources.

Operation Section

The Operation section is a reference for the new operator and a refresher for the experienced operator.

Photographs and illustrations guide the operator through correct procedures for using the tool group.

Operating techniques outlined in this publication are basic. Skill and techniques develop as the operator gains knowledge of the service tool and the tools capabilities.

Maintenance Section

The Maintenance section is a guide to tool inspection, cleaning, storage, and tool disposal

Service Parts Section

The Service Parts section is a reference for parts identification and available part numbers.

Safety Icon Nomenclature

Personal Protection/Important Information

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Personal Protection/Important Information

Prohibited Action

No smoking

Hazard Avoidance

Crushing hazard (foot)

Crushing hazard (hand)

Pinch point

Fire hazard

Electrical Shock - Hazard

Fire hazard

General Information Section

Introduction

The 193-4124 Rear Wheel Bearing Preload Adjuster is used to determine the shim thickness required for a proper preload setting. Because no calculations are required, adjustment time is reduced, there is less chance of error, and accuracy is improved over conventional methods.

The bearing preload adjuster is used when the rear wheel assembly is in a spindle-down, vertical orientation only.

Included with the bearing preload adjuster is a precision base plate (ensures accuracy), two indicators, all attachments, and center lifting ring (used with lifting device). The rugged design of the tool ensures long life and also helps the tool to maintain accuracy.

The preload force applied by this tool is approximately 5216 kg (11,500.0 lbs) which represents the same force applied to the bearings when the wheel assembly is installed on the truck. The adjuster is designed with a 3.175 mm (.1250 in) offset between the spindle end and surface of the hub.

Illustration 3	g02646620
193-4124 Rear Wheel Bearing Preload Adjuster. (1) Preload Adjuster. (2 ) M24 Bolts. (2a) Spherical Washer. (3) Digital Indicators. (4) Lifting Eyes. (5) Outer Contact Ring. (6) Base Plate. (7) Calibration Shims. (8) Shim Retaining Bolts. (9) Leveling Legs.

Note: The top plate of this preload adjuster has slotted holes for the six M24 bolts, which allow the plate to be used on all 793 Off-Highway Trucks including the 793D. If the top plate does not have the slotted holes, contact Dealer Service Tools to have the preload adjuster reworked.

Note: The base plate is designed with 12 M24 bolt holes (two complete sets). Because of the constant wear to the bolt hole threads from repeatedly removing and installing the bolts, this additional set of bolt holes provides greater tool life. If one hole is damaged, rotate the bearing preload adjuster and use the other set of bolt holes. If one hole in each set of bolt holes is damaged on the top side of the plate, the plate can be flipped over, providing two more complete sets of bolt holes.

References

Special Instruction, NEHS0905, " 245-1893 Calibration Group Used to Calibrate the Bearing Preload Adjusters for Off-Highway Trucks"

Additional Contact Information

For additional product support questions concerning this tool, contact the Dealer Service Tools Hotline at:

USA: 800-542-8665, Option 1

International: 1-309-578-7372

E-mail: dealerservicetool_hotline@cat.com

Note: Continuing improvement and advancement of product design can mean some photographs or illustrations in this publication will show details that are different from your service tool.

Prior to Adjustment Procedure

The bearing preload adjuster is shipped from the factory with leveling legs (9) installed on top of the base plate. Before using the bearing preload adjuster, remove the leveling legs and install them on the bottom of the plate, making sure that the plate sits level. Also, make sure that the indicator tips are not loose.

The bearing preload adjuster should be allowed to acclimate to the ambient temperature of the surrounding conditions for at least 4 hours prior to being used.

Once the indicators are set to zero, it is not necessary to reset the indicators after each preload operation. However, the adjuster should be set to zero before each work shift, if the bearing preload adjuster has been in storage, or if the preload adjuster has been unused for more than one day. The tool should also be reset after the fourth preload procedure within one shift.

Operation

Preload Procedure

This procedure is written with the rear wheel assembly in a spindle-down, vertical orientation. Before starting the procedure, the wheel assembly should be assembled to the point of being ready for the bearing preload procedure.

1. Remove six M24 bolts (2) from the bearing preload adjuster and separate it from base plate (6). Clean all six M24 bolts, spherical washers (2), and all mating surfaces of outer contact ring (5), inner spacer (10), Illustration 6), and base plate (6) .

   Note: Check for any burrs, nicks, or raised surfaces which exceed 0.025 mm (.0010 inch) on or above the surface of both the outer contact ring and base plate. Remove any raised surfaces using a file or stone. Raised surfaces will affect the accuracy of this tool and the preload adjustment to the wheel bearing.

2. Lubricate the M24 bolt threads with machine oil or anti-seize lubricant. Attach the bearing preload adjuster to base plate using the six bolts and spherical washers.

3. Tighten bolts (2) to 335 N·m (250.0 ft/lb) using an alternating diagonal pattern with no more than one-quarter turn at a time. The alternating tightening pattern ensures that the adjuster is tightened evenly onto the base plate. Do not use an impact wrench to tighten bolts (2) on the bearing preload adjuster.

4. Select the units of measure (millimeter or inch) on the indicators. Set the two digital indicators to zero by pressing the "zero button" on each indicator.

5. Loosen and remove the six bolts. Use the same one-quarter turn and alternating diagonal pattern when loosening the bolts. Do not use an impact wrench to remove the bolts.

6. Clean and check the wheel spindle end and hub contact surface for nicks, burrs, or raised surfaces. Chase all spindle bolt hole threads with an M24 tap to ensure that the threads are clean before installing the bolts.

7. Attach an overhead lifting device to the center lifting ring. Remove the bearing preload adjuster from the base plate and place it in position on the wheel assembly.

8. Attach the bearing preload adjuster using six bolts. Tighten the bolts to 335 N·m (250.0 ft/lb) using an alternating diagonal pattern with no more than one-quarter turn at a time. The alternating tightening pattern ensures that the adjuster is tightened evenly onto the wheel spindle. Do not use an impact wrench to tighten the bolts.

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Illustration 4	g02646624
Bearing Preload Adjuster Attached To Wheel Assembly.

9. Release the parking brake and rotate the wheel at least three revolutions to allow the wheel bearing to seat properly.

10. Record the readings from each digital indicator and average these readings to calculate the correct shim pack thickness.

11. Loosen and remove the six bolts. Use the same one-quarter turn and alternating diagonal pattern when loosening the bolts. Do not use an impact wrench to remove the bolts.

12. Using an overhead lifting device, remove the tool from the wheel assembly.

13. Clean the surface of the outer contact ring and base plate. Place the bearing preload adjuster tool onto the base plate and tighten the six bolts, finger tight.

14. Install the shim pack, retainer, and bolts on the wheel assembly. Tighten the bolts per Caterpillar specifications. The bearing preload procedure is now complete.

Indicator Accuracy Check

To check the indicators for accuracy:

1. Remove six M24 bolts (2) from the bearing preload adjuster and separate from the base plate (6). Thoroughly clean bolts and spherical washers (2) and all mating surfaces of outer contact ring (5) and the base plate.

   Note: Check for any burrs, nicks, or raised surfaces which exceed 0.025 mm (.0010 inch) on or above the surface of both the outer contact ring and base plate. Remove any raised surfaces using a file or stone. Raised surfaces will affect the accuracy of this tool and the preload adjustment to the wheel bearing.

2. Lubricate the M24 bolt threads with machine oil or anti-seize lubricant. Attach the bearing preload adjuster to base plate using the six bolts and spherical washers.

3. Tighten bolts (2) to 335 N·m (250 ft/lb) using an alternating diagonal pattern with no more than one-quarter turn at a time. The alternating tightening pattern ensures that the adjuster is tightened evenly onto the base plate. Do not use an impact wrench to tighten the bolts.

4. Select the units of measure (millimeter or inch) on the indicators. Set the two digital indicators to zero by pressing the "zero button" on each indicator.

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Illustration 5	g02646626
Set Each Indicator To Zero.

5. Loosen and remove the six bolts. Use the same one-quarter turn and alternating diagonal pattern when loosening the bolts. Do not use an impact wrench to remove the bolts.

6. Remove calibration shims (7) from the base plate by removing four bolts (8) holding the calibration shims in place. Position calibration shims (7), equally spaced, under outer contact ring (5), as shown in Illustration 6.

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NOTICE
Make sure that the calibration shims are not underneath or in contact with inner spacer (10). Damage to the contact ring or base plate can occur if the calibration shims are under the contact ring when the bearing preload adjuster is tightened onto the base plate.

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Illustration 6	g02646629
Preload Adjuster Attached To Base Plate. (The Illustration Shows The Calibration Tool In The Compressed State.) (3) Indicator. (5) Outer Contact Ring. (6) Base Plate. (7) Calibration Shims. (10) Inner Spacer. (11) Indicator Extension Tip.

7. Retighten the bolts to 335 N·m (250.0 ft/lb) using an alternating diagonal pattern with no more than one-quarter turn at a time. Do not use an impact wrench to tighten the bolts.

8. Each indicator reading should be 3.175 ± 0.051 mm (0.1250 ± 0.0020 inch). If the indicators do not show this reading:
   • clean all mating surfaces and recheck,

   • make sure that the indicators are securely fastened to the bearing preload adjuster, and/or

   • make sure that the indicator tips are not loose.

   After completing these three items, repeat Steps 3 through 8.

Illustration 7	g02646655

If the 3.175 mm (.1250 inch) reading still cannot be obtained, contact the Dealer Service Tools hotline by phone 1-309-675-6277 or email dealerservicetool_hotline@cat.com to obtain further technical support contact information.

Maintenance

Storage

• Hand tighten the M24 bolts holding the bearing preload adjuster to the base plate. The springs of the bearing preload adjuster should never be stored in a compressed position.

• The tool and base plate should be covered (kept in the original shipping box) to keep out dirt and moisture.

• A light coating of oil is recommended to prevent rust.

• Store in a clean, dry environment.

Service and Warranty

Complete and return the attached Warranty Registration Sheet within two weeks of receiving the bearing preload adjuster.

This tool should be calibrated a minimum of every 12 months, using the 245-1893 Calibration Group .

If technical support is required, begin the process by contacting the Dealer Service Tools hotline by phone (1-309-675-6277) or email dealerservicetool_hotline@cat.com.

Serviceable Parts