Reuse and Salvage for Gear Train and Gear Shafts on Engines {0679, 1151, 1162, 1206} Caterpillar

Caterpillar Products

All Cat Engines

Introduction

Table 1

Revision	Summary of Changes in SEBF9244
10	Added New SN Prefixes.
08–09	Corrected callouts.- Added C175 aux and PTO shafts.
07	Combined information from M0068228, SEBF8045, SEBF8188, SEBF8377, SEBF9191, SEBF9192, SEBF9316, added 29 part numbers and repaired 14 pixelated illustrations.

© 2019 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 Reuse and Salvage Guideline contains the necessary information to allow a dealer to establish a parts reusability program. Reuse and salvage information enables Cat dealers and customers to benefit from cost reductions. 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 Reuse and Salvage Guideline must be used with the latest technical information that is available from Caterpillar.

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.

Important Safety Information

Illustration 1	g02139237

Work safely. 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. Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, a procedure, a work method, or operating technique that is not recommended by Caterpillar is used, then ensure that the procedure is safe for you and other people. Ensure that the product will not be damaged or the product will not be made unsafe by the operation, lubrication, maintenance, or the repair procedures that are used.

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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 operation, lubrication, maintenance and repair information.

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 which is followed by a signal word such as danger, warning, or caution. The "WARNING" safety alert symbol is shown 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.

Summary

The illustrations in this guideline show specific examples of reusability for gears and gear shafts for engines. Normally, the reusability of the gears is determined from the condition of the gear teeth. Damage in other areas on the gear is not common and easily identified.

If a gear is within the specifications in this guideline, the gear can be expected to give normal performance until the next overhaul when the gear is used again in the same application. Correct all conditions that damaged the gear.

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.

Service Letters and Technical Information Bulletins

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NOTICE
The most recent Service Letters and Technical Information Bulletins that are related to this component shall be reviewed before beginning work. Often Service Letters and Technical Information Bulletins contain upgrades in repair procedures, parts, and safety information that pertain to the parts or components being repaired.

References

Table 2

References
Media Number	Title
SEBF8187	Reuse and Salvage Guidelines, "Standardized Parts Marking Procedures".
SEBF9066	Applied Failure Analysis, "Guideline for Examining Failed Parts".
SEHS9826	Special Instruction, "Ordering "Series B" Replacement Cylinder Blocks for 3500 Series Engines"

Tooling and Equipment

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NOTICE
Failure to follow the recommended procedure or the specified tooling that is required for the procedure could result in damage to components. To avoid component damage, follow the recommended procedure using the recommended tools.

Table 3

Required Tooling and Equipment
Part Number	Description
1P-3048	Wrench Assembly
1P-3537	Dial Bore Gauge Kit
3P-1568	Dial Indicator
4C-9442	Flashlight
4C-9991	Tool Group
5P-4160	Tip
5P-4456	Base
5P-6518	Dial Indicator Fixture
6V-2010	Polishing Stone
6V-7059	Micrometer
8S-2257	Eye Loupe
8T-5096	Dial Indicator Group
9A-1593	Surface Texture Comparison Gauge
222-3062	Air Drill
262-8390	Pocket Microscope 40X
303-9339	Lint Free Shop Towels
385-9422	Micrometer Extensions, Internal 50 - 609 mm (2 - 24 inch)
423-4373	Digital Caliper 0.0 - 203.2 mm (0.00 - 8.00 inch)
431-4150	Micrometer, External 25 mm (1 inch)
448-3698	Profilometer
473-8688 or 473-8689	Micrometer, Inside 2.00 - 12.00 inch
	Micrometer, Inside 50 - 300 mm
473-8690	Micrometer, Outside 0.00 - 4.00 inch
473-8691	Outside Electronic Micrometer Set 2-6 inch
473-8692	Micrometer, Outside 152.4 - 304.8 mm (6.00 - 12.00 inch)
474-3709 or 474-3710	Micrometer, Inside (8.00 - 32.00 inch)
	Micrometer, Inside 200 - 800 mm
549-3500	Precision Gage Pin Set
549-3505	Precision Gage Pins 4.000 mm (0.15748 inch)
549-3506	Precision Gage Pins 5.000 mm (0.19685 inch)
549-3508	Precision Gage Pins 6.000 mm (0.23622 inch)
549-3510	Precision Gage Pins 8.000 mm (0.31496 inch)
549-3512	Precision Gage Pins 10.000 mm (0.39370 inch)
FT3302	TIR Tooling
-	Carbide tipped drill bit 5.94 mm (0.234 inch)
-	Cobalt drill bit 5.94 mm (0.2339 inch)
-	Precision Gage Pins 4.7625 mm (0.18750 inch)
-	Precision Gage Pins 6.350 mm (0.25000 inch)

Standardized Parts Marking Procedure

Reference: SEBF8187Reuse and Salvage Guidelines, "Standardized Parts Marking Procedures".

The code is a Cat standard and is used to record the history of a component. The code will identify the number of rebuilds and hours at the time of each rebuild. This information is important and should be considered for any decision to reuse a component.

Ensure that the mark is not covered by a mating part. Use a metal marking pen to mark the code onto the component.

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NOTICE
Do not use numbering stamp punches to mark internal components. The impact from striking the stamp will cause an abnormal stress riser. The added stress riser may cause premature part failure.

Illustration 3	g06124077
DO NOT use numbering stamp punches to mark internal components.

The procedure for marking components is a Cat standard. This code is helpful when the machine is sold into a different territory after the first rebuild. During an overhaul, the previous code of a part should never be removed.

Example 1

Illustration 4	g03856853
Typical Example

Illustration 4 shows code (1-15). The first number (1) indicates that the gear had been rebuilt once. The second number (15) indicates that there were 15,000 hours on the gear at the time of rebuild.

Example 2

Illustration 5	g03856857
Typical Example

Illustration 5 shows code (1-12) and code (2-10). Code (2-10) represents the information from the second rebuild. The first number (2) indicates that the gear had been rebuilt twice. The second number (10) indicates that 10,000 hours accumulated on the gear between the first and second rebuild.

Note: Add the first and second rebuild hours to obtain the total number of hours for the gear in Illustration 5. In this example, the gear has a total of 22,000 hours.

Measurement Requirements

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NOTICE
Precise measurements shall be made when the component and measurement equipment are at 20° (68° F). Measurements shall be made after both the component and measurement equipment have had sufficient time to soak at 20° (68° F). This will ensure that both the surface and core of the material is at the same temperature.

Prepare the Area for Inspection

Reference: , SEBF9066Applied Failure Analysis, "Guideline for Examining Failed Parts".

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Personal injury can result when using cleaner solvents. To help prevent personal injury, follow the instructions and warnings on the cleaner solvent container before using.

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Personal injury can result from air pressure. Personal injury can result without following proper procedure. When using pressure air, wear a protective face shield and protective clothing. Maximum air pressure at the nozzle must be less than 205 kPa (30 psi) for cleaning purposes.

The first step of visual examination is to prepare the surface of the part for inspection. Even thin layers of oil, grease, or other materials may hide important facts. Generally, aggressive cleaning methods employing harsh chemicals, glass beads, soda blasting, or hand scrubbing should be avoided as these methods can remove facts that aid in determining the type and location of additional testing that may be needed. Soft brushes and mild solvents usually work best for cleaning parts.

Illustration 6	g01201262
These cleaning methods should be avoided on parts. Surface damage during cleaning is likely.

To summarize cleaning requirements for parts, remember that the objective is to not further damage or wear areas before the areas can be inspected. Keep in mind these things when cleaning parts:

• Remove all removable plugs before cleaning.

• Use appropriate thread taps to chase all threaded holes.

• Use a fast drying, mild solvent to soak and/or rinse parts clean.

• Make sure that you remove all debris, paint, and oil but Do Not wipe, scrub, or scratch to clean part.

• When you move parts that require cleaning, always use a proper lifting device. This device must protect the part from damage. For the safety of the operator, all lifting devices must be inspected before use.

• Do not wipe parts with a shop towel to dry, air dry, blow with dry compressed air, or blot dry with a paper towel.

Polishing

Note: Do not use polishing stone on shaft journals.

Illustration 7	g03885189
6V-2010 Polishing Stone and oil should be used to polish a tooth. Be aware of the adjacent tooth. The corner of the stone can easily damage adjacent teeth.

Illustration 8	g03885193
A grinder had been used on this gear in an attempt to recondition the teeth. Use 6V-2010 Polishing Stone and oil for reconditioning the teeth on a gear. Do not use a grinder. The grinding process can remove the case hardened surface of a gear. DO NOT USE THIS PART AGAIN.

Gears with limited damage on the surface may be used again after the damaged area has been polished with 6V-2010 Polishing Stone and oil. Caterpillar recommends the use of a polishing stone and oil. Never use a die grinder to recondition a gear. Refer to Illustration 8.

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NOTICE
If the tooth has a raised metal area, remove only the raised portion. Do not try to remove pitting or any other recessed surface damage. Do not use a grinder or power polisher, use only a hand-held stone. Using power tools to remove damage can also remove the case hardened surface of the gear, causing eventual failure.

Nomenclature for Front and Rear Gear Train

3500 Front Gear Train

Illustration 9	g06289580
(1) High-Speed Idler Gear or Low Speed Idler Gear (2) Bearing Sleeve for Adapter Assembly (3) Bearing Sleeve (4) Accessory Drive Gear

3500 Rear Gear Train

Illustration 10	g06177134
(1) Ring (2) Camshaft Drive Gear (3) Idler Gear Assembly (4) Bearing Sleeve (5) Thrust Washer (6) Bolt (7) Cluster Gear Shaft (8) Idler Gear Shaft (9) Bolt (10) Bolt (11) Bearing Sleeve (12) Bolt (13) Hard Washer (14) Cluster Gear Assembly (15) Thrust Plate (16) Plate (17) Bolt (18) Bolt (19) Crankshaft Gear

C175 Front Gear Train

Illustration 11	g06312890
(1) Fuel Pump Adapter (2) Oil Pump Adapter (3) Bearing Sleeve (4) Low Speed Idler Gear, Medium Speed Idler Gear, or High-Speed Idler Gear (5) Crankshaft Gear (6) Low, Medium, or High-Speed Accessory Drive Gear (7) Pump Drive Shaft (8) Bearing Sleeve (9) Front Adapter (10) Idler Shaft

Illustration 12	g06312895
Accessory Drive Gear (6) and Idler Gear (4). (A) High-Speed Drive Gear (B) Medium Speed Drive Gear (C) Low Speed Drive Gear

TheC175 Engines use either a low, medium, or high-speed accessory drive. The HIGH speed models use a 53 Tooth Idler Gear (5) and a 61 Tooth Accessory Drive Gear (7). The MEDIUM speed models use a 57 Tooth Idler Gear (5) and a 53 tooth Accessory Drive Gear (7). The LOW speed models use a 64 Tooth Idler Gear (5) and a 41 tooth Accessory Drive Gear (7). Make sure to check your gears to be sure that the correct dimensions are used.

C175 Rear Gear Train

Illustration 13	g06289603
(1) Camshaft (2) Camshaft Gear (3) Cluster Gear Shaft (4) Idler Gear (5) Bearing Sleeve (6) Crankshaft Gear

Visual Inspection of Gears

Glossary

Excessive - Exceeding acceptable amounts

Machining - Finish a surface with a machine.

Pitting - Small holes from corrosion and wear

Polished - Surface that is smooth and shiny as a result of wear

Nomenclature of Gear Tooth

Positive identification of the type of damage on a gear is important. Remember to check all the gear teeth.

Use the following tools to identify damaged areas during the inspection process:

• Magnifying glass

• Strong light source

• White paper

Illustration 14	g01625725
(1) End (2) Tip (3) Edge (4) Face of the Tooth (5) Pitch line (6) Radius (7) Profile

Illustration 15	g01625728
Teeth on a new gear

Effects of Wear

Illustration 16	g01625742

The polished areas are examples of normal wear.

Use the gear again.

Illustration 17	g01625753

The gears that are shown in Illustration 16 and Illustration 17 show some loss of material from the teeth in addition to areas that are polished.

Use the gear again.

Illustration 18	g01625757

The areas indicate a typical area of normal wear.

Use the gear again.

Do not use the gear again if either side of the worn area can be felt with a fingernail.

Illustration 19	g01625766

The areas of wear show some light corrosion.

Use the gear again.

Illustration 20	g01625767

Oil can cause discoloration on sections of some teeth.

Use the gear again.

Illustration 21	g01625789

The surfaces of the gear teeth are not polished. Not polished gear teeth surfaces are an indication of excessive wear. Also see Illustration 22.

Do not use the gear again.

Illustration 22	g01625797

The faces of the gear teeth are not polished. Not polished gear teeth faces are an indication of excessive wear.

Do not use the gear again.

Illustration 23	g01625800

Excessive wear has destroyed the profiles of the teeth.

Do not use the gear again.

Illustration 24	g01625801

The amount of wear is different on each tooth.

Do not use the gear again.

Effects of Pitting

Illustration 25	g01625805

Pitting on the ends of the teeth

Use the gear again.

Illustration 26	g01625808

Pitting at the pitch line of each tooth

Do not use the gear again.

Illustration 27	g01625809

Pitting in the radius of each gear tooth

Do not use the gear again.

Illustration 28	g01625811

Illustration 29	g01625812

Illustration 30	g01625814

Examples of heavy pitting

Do not use the gear again.

Illustration 31	g01625821

Illustration 32	g01625822

Examples of heavy pitting and excessive wear

Do not use the gear again.

Illustration 33	g01625823

Light pitting that has been polished.

Use the gear again.

Effects of Machining

Illustration 34	g01625844

Illustration 35	g01625845

The gear teeth contain marks from machining and some light pitting.

Use the gear again.

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NOTICE
Know the difference between the type of lips shown here and lips that result from severe plastic yielding. Refer to the "Severe Plastic Yielding" section of this guideline.

Illustration 36	g01625872

Machining can sometimes cause lips on both edges of the gear tooth.

Use the gear again.

Use the gear again only if the lips are of even height.

Illustration 37	g01625880

Typical marks from machining

Use the gear again.

Note: Illustration 37 is not a gear. However, these marks appear similar on all gears.

Illustration 38	g01625892

Illustration 39	g01625893

Typical horizontal and vertical machining marks

Use the gear again.

Nicks, Cracks, and Other Damage to the Surface

Illustration 40	g01626112

Small nicks on one edge and the tip of a tooth

Use the gear again.

Use the gear again after the sharp edges of the nick are smoothed with a 6V-2010 Polishing Stone.

Illustration 41	g01626115

A small nick on the face of the tooth

Use the gear again.

Use the gear again after the sharp edges of the nick are smoothed with a 6V-2010 Polishing Stone.

Illustration 42	g01626116

A nick on the end of a tooth

Use the gear again.

Use the gear again after the sharp edges in the immediate area of the face of the tooth are smoothed with a 6V-2010 Polishing Stone.

Illustration 43	g01626122

A crack in the end of a tooth

Do not use the gear again.

Illustration 44	g01626125

A deep gouge across the center of the tooth face.

Do not use the gear again.

Illustration 45	g01626129

Raised ridges along the faces of the teeth

Do not use the gear again.

Severe Plastic Yielding

Severe plastic yielding is caused by a heavy flow of surface material. Severe plastic yielding results in the development of lips on the ends, edges, and/or tips of the gear teeth. Severe plastic yielding causes uneven lips, whereas lips from machining are even. Refer to Illustration 36 for machining lips.

Illustration 46	g01626173

This gear is a typical example of severe plastic yielding. The lips are not of even height.

Do not use the gear again.

Illustration 47	g01626179

This gear contains severe plastic yielding. The lips are not of even height.

Do not use the gear again.

Scoring

Illustration 48	g01626182

Vertical lines on the face of the tooth are indications of scoring.

Use the gear again.

Note: Scoring is not a common problem in gears.

Fuel Pump Gear Inspection

1. Perform gear inspection, if the gear passes visual inspection of the gear continue to checking end play. If the gear does not pass inspection replace the gear.
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   Illustration 49	g06266455

2. With the gear standing upright on a table, hold the outer gear tightly with one hand while trying to rotate the inner hub with the other hand. Look and feel for movement between the two pieces. Movement may feel like clicking or knocking. There should be no movement between the hub and outer gear. If there is movement between the hub and gear replace the gear.
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   Illustration 50	g06026282

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   Illustration 51	g06266456

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   Illustration 52	g06026327

3. Fasten tooling FT3302 with two bolts and nuts.
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   Illustration 53	g06026334

4. Place the plate from tooling FT3302 on a suitable work surface. Secure the plate to the work surface. The clamps used to secure the plate must be outside the radius of the pins.
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   Illustration 54	g03891436

5. Place the dial indicator into a hole next to tooling FT3302. Zero dial indicator.
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   Illustration 55	g03891400

6. Attach torque wrench to tooling FT3302. Apply 35 N·m (26 lb ft). Observe TIR reading and record when 35 N·m (26 lb ft) is reached. The limit for reuse is 0.045 mm (0.0018 inch) at 35 N·m (26 lb ft). If the gear does not meet the TIR specification the gear should be replaced. The gear is not serviceable.

Wear Limit for Bronze Thrust Washers

Table 4

Hub Motion Relative to the Gear
	Radial	Axial
New	0.06 - 0.12 mm (0.00236 - 0.00472 inch)	0.19 - 0.31 mm (0.00748 - 0.01220 inch)
Maximum Wear	0.15 mm (0.00591 inch)	0.037 mm (0.00146 inch)

Visual Inspection of Gear Shafts

Note: Ensure that all removable plugs are removed before visual inspection, if plugs are not removed, remove and perform the cleaning process.

Critical Areas on Gear Shafts

The surfaces at location (A) & (B) are critical to the performance of the shaft and must conform to the reuse specifications for surface texture and diameter. Reconditioning of these surfaces is not recommended. Check location (C), for wear steps and make sure that the Oil Holes (D) are free of debris by flushing the holes with oil.

Illustration 56	g06323759
Visual reference example of C175 and 3500 auxiliary shafts

Illustration 57	g06323789
Visual reference example of C175 oil & water pump shafts

Illustration 58	g06324088
Visual reference example of C175 idler shafts

Illustration 59	g06332367
Visual reference example of 3500 PTO shafts

Illustration 60	g06324150
Visual reference example of C175 PTO shafts

Illustration 61	g03327456
Check the splines of the gear shaft for wear steps.

Examples of Acceptable Wear on Gear Shafts

Nicks and Dings

Most nicks and dings are acceptable as long as the shaft meets minimum surface texture and other reuse specifications.

Illustration 62	g03326412
Use Again if Shaft Meets Minimum Specifications.

Illustration 63	g03421276
Use Again if Shaft Meets Minimum Specifications.

Scratches and Light Rust

Gear shafts with scratches and light rust can be reused as long as the shaft meets minimum specifications after cleaning with non-abrasive methods.

Illustration 64	g03327542
Use Again if Shaft Meets Minimum Specifications.

Illustration 65	g03327546
Use Again if Shaft Meets Minimum Specifications.

Other Acceptable Damage Types

Illustration 66	g03327468
Minor damage on the wear sleeve surface. Use Again if Shaft Meets Minimum Specifications.

Illustration 67	g03327484
Rough surface on a non-critical area of Idler Shaft. Use Again if Shaft Meets Minimum Specifications.

Examples of Unacceptable Wear on Gear Shafts

Gear shafts can be reused as long as the shaft meets the minimum specifications in the critical areas shown in Illustration 56 - 60. Shafts with small nicks are acceptable, and the shaft must meet minimum specifications and there are no raised material surrounding the nick.

Illustration 68	g03326367
This shaft has excessive amounts of corrosion in a critical area (A) and cannot be reused. Do Not Use Again.

Illustration 69	g06322894
This shaft has excessive amounts of corrosion in a critical area (B) and cannot be reused. Do Not Use Again.

Illustration 70	g03327549
There are heavy scratches and corrosion and significant raised material on the gear shaft. Do Not Use Again.

Specifications for Auxiliary, Oil & Water Pump Shafts

Illustration 71	g06332338

Table 5

Auxiliary, Oil & Water Pump Shaft Diameters and Surface Textures
Part Number	Diameter of Shorter End of Shaft (A)	Surface Texture of Shorter End of Shaft (B)	Minimum Length (C) for Surface Texture of (E)	Diameter of Longer End of Shaft (D)	Surface Texture of Longer End of Shaft (E)
246-6691	Ø 74.9 ± 0.015 mm (2.949 ± 0.0006 inch)	0.80 µm (31.49606 µinch) Ra	40 mm (1.575 inch)	Ø 74.9 ± 0.015 mm (2.949 ± 0.0006 inch)	0.80 µm (31.49606 µinch) Ra
251-5516				Ø 93.9 ± 0.015 mm (3.696 ± 0.0006 inch)
259-2489				Ø 74.9 ± 0.015 mm (2.949 ± 0.0006 inch)
331-3656

Specifications for Idler Shafts

Illustration 72	g06332334

Table 6

Idler Shaft Diameters and Surface Textures
Part Number	Diameter of Larger End of Shaft (F)	Surface Texture of Larger End of Shaft (G)	Diameter of Smaller End of Shaft (H)	Surface Texture of Smaller End of Shaft (J)
7C-3260	Ø 129.86 ± 0.05 mm (5.11259 ± 0.00197 inch)	5.5 µm (216.5354µinch) Ra	Ø 89.88 ± 0.02 mm (3.53858 ± 0.00079 inch)	0.80 µm (31.49606 µinch) Ra
250-9947			Ø 105.88 ± 0.02 mm (4.16850 ± 0.00079 inch)
277-6911			Ø 89.88 ± 0.02 mm (3.53858 ± 0.00079 inch)
282-8915			Ø 105.88 ± 0.02 mm (4.16850 ± 0.00079 inch)
329-8192	Ø 161.73 ± 0.05 mm (6.36731 ± 0.00197 inch)	< 3.5 µm (< 137.7953 µinch) Ra	Ø 119.814 ± 0.012 mm (4.71708 ± 0.00047 inch)
430-8141

Specifications for PTO Shafts

Illustration 73	g06332666

Illustration 74	g06332700

Table 7

PTO Shaft Diameters and Surface Textures
Part Number	(K)	Surface Texture (L)	(M)	Surface Texture (N)	(P)	Surface Texture (R)	(S)	Surface Texture (T)
4P-3743	Ø 59.946 ± 0.013 mm (2.36007 ± 0.00051 inch)	1.6 µm (62.99213 µinch) Ra	Ø 63.42 ± 0.013 mm (2.49685 ± 0.00051 inch)	0.2 µm (7.87401 µinch) Ra	Ø 95.0 ± 0.015 mm (3.74015 ± 0.00059 inch)	< 3.5 µm (< 137.7953 µinch) Ra	Ø 63.42 ± 0.013 mm (2.49685 ± 0.00051 inch)	0.2 µm (7.87401 µinch) Ra
289-6329	Ø 57.897 ± 0.05 mm (2.27940 ± 0.00197 inch)	35 µm (1377.953 µinch) Ra	Ø 63.43 ± 0.01 mm (2.49724 ± 0.00039 inch)		Ø 95.0 ± 0.015 mm (3.74015 ± 0.00059 inch)		Ø 63.43 ± 0.01 mm (2.49724 ± 0.00039 inch)
290-1630					Ø 101.5 ± 0.015 mm (3.99606 ± 0.00059 inch)
315-3096	Ø 59.946 ± 0.013 mm (2.36007 ± 0.00051 inch)	1.6 µm (62.99213 µinch) Ra	Ø 63.42 ± 0.013 mm (2.49685 ± 0.00051 inch)		Ø 95.0 ± 0.015 mm (3.74015 ± 0.00059 inch)		Ø 63.42 ± 0.013 mm (2.49685 ± 0.00051 inch)

Sleeve Installation and Machining Procedure

Fuel Pump Adapter Assembly

Illustration 75	g06289620

Note: When you are installing the bearing sleeve, the hole in the bearing sleeve must be aligned with oil passage (B).

Table 8

291-1998 and 354-1562 Pump Adapter Assembly with 318-4810 Bearing Sleeve
Dimension	Description	Dimension
A	Bore diameter of adapter after sleeve installation	94.056 mm (3.70298 inch)

Engine Oil Pump Adapter Assembly

Illustration 76	g06289621

Note: When you are installing the bearing sleeve, the hole in the bearing sleeve must be aligned with oil passage (E). The hole in the bearing sleeve has a position tolerance of 3.0 mm (0.11811 inch) from datum (1).

Table 9

348-7075 Engine Oil Pump Adapter Assembly with 348-7074 Bearing Sleeve
Dimension	Description	Dimension
C	Diameter of bearing bore after sleeving	75.023 mm (2.95366 inch)

Table 10

Former 247-3417 Engine Oil Pump Adapter Assembly with 127-5400 Bearing Sleeve Rework with 348-7074 bearing sleeve with the dimensions below
Dimension	Description	Dimension
C	Diameter of bearing bore after sleeving	75.0 ± 0.055 mm (2.95275 ± 0.00217 inch)

Front Adapter Assemblies

Illustration 77	g06289632

Note: When you are installing the bearing sleeve, the hole in the bearing sleeve must be aligned with oil passage (H).

The bearing sleeve should be installed so that the bearing sleeve is flush with surface (G) +/- 0.5 mm (0.019 inch).

Table 11

348-7076 Front Adapter Assemblies with 348-7074 Bearing Sleeve
Dimension	Description	Dimension
F	Diameter of bearing bore after sleeving	75.035 mm (2.95413 inch)

Table 12

Former 248-7582 Front Adapter Assemblies with 127-5400 Bearing Sleeve Rework with 348-7074 bearing sleeve with the dimensions below
Dimension	Description	Dimension
F	Diameter of bearing bore after sleeving	75.0 ± 0.055 mm (2.95275 ± 0.00217 inch)

Low, Medium, and High-Speed Idler Gears

Illustration 78	g06312920

Table 13

Low, Medium, and High-Speed Idler Gear Assemblies
Part Number	Machined Diameter of Bearing Sleeve After Installation (I)	Installation Depth (J)	Surface Texture (K)
307-2402	89.964 ± 0.01 mm (3.54188 ± 0.0004 inch)	2.3 ± 0.5 mm (0.0905 ± 0.0197 inch)	0.80 µm (31.49606 µinch) Ra
312-1676	105.98 ± 0.01 mm (4.1724 ± 0.0004 inch)
312-1677

Idler (Cluster) Gear and Shaft

Illustration 79	g06332306

Table 14

254-5886 Idler (Cluster) Gear with 254-5887 Bearing Sleeve
Dimension	Description	Dimension
A	Machined Diameter of Bearing Sleeve	75.06 ± 0.01 mm (2.9551 ± 0.0004 inch)
B	Installation Depth	2 ± 0.5 mm (0.08 ± 0.02 inch)
C	Surface Texture	0.80 µm (31.49606 µinch) Ra

Illustration 80	g06332307
Example of cluster gear shaft

Table 15

328-7113 Cluster Gear Shaft
Dimension	Description	Dimension
D	Shaft Diameter	74.97 ± 0.01 mm (2.9516 ± 0.0004 inch)
E	Surface Texture	0.13 µm (5.11811 µinch) Ra

Illustration 81	g06312800
Example of idler and cluster gear

Table 16

Idler and Cluster Gear Specifications
Part Number	Surface Texture (F)	Installation Depth (G)	Machined Diameter of Bearing Sleeve After Installation (H)	Diameter of Original Gear Bore (J)
478-5468	0.80 µm (31.49606 µinch) Ra	1 ± 0.5 mm (0.03937 ± 0.01969 inch)	119.93 ± 0.01 mm (4.72164 ± 0.00039 inch)	128.009 ± 0.013 mm (5.03971 ± 0.00051 inch)
478-5469

Illustration 82	g06312830
Example of auxiliary drive gear

Table 17

Auxiliary Drive Gear Specifications
Part Number	Diameter of Original Gear Bore (K)
245-1357	95.05 ± 0.025 mm (3.74212 ± 0.00098 inch)
273-3816	101.551 ± 0.025 mm (3.99806 ± 0.00098 inch)

Salvage Procedures for Front and Rear Gear Train on 3500 Engines

On 3500 Engines, the bearing sleeves on the front gear train have been improved to increase the life of the bearing sleeve and the gear train reliability and several refinements have been made to improve the service life and reliability of the rear gear trains.

Improvements to the Front Gear Train

New bearing sleeves were released for the following:

• Low Speed Idler Gears

• High-Speed Idler Gears

• Adapter Assemblies

These bearing sleeves have increased durability and resistance to cavitation erosion and fatigue.

In addition, the bearing sleeve is machined after assembly. The machining of the bearing sleeve provides better control of the clearance of the bearing sleeve to shaft. The machining also improves bearing resistance to fatigue. The adapter bearing sleeve needs no machining after assembly.

With the change of the bearing material, the interference fit between the bearing sleeve and gear or bearing sleeve and the adapter has also changed. The new interference fit will help retain the bearing sleeve in the mating part.

As a result of reconditioning or replacing existing parts, older engines can gain the same benefits as newer engines.

Table 18

Part Numbers for the Bearing Sleeve
Description	Former Bearing Sleeve	New Bearing Sleeve
High-Speed Idler Gear Assembly	7N-5243	140-9597
Low Speed Idler Gear Assembly	8N-5301	116-1365
Adapter Assembly	7N-5244	127-5400

Affected Engines

The improvements to the 3500 Engines came in three stages. The first stage was the release of the new bearing sleeve for the low speed idler gear assembly. The engines with this change and the serial numbers are listed in Table 19. All the attachments that are low speed drives that were made after October 1996have the new bearing sleeves on the front idler gear assemblies.

Table 19

Effective Serial Numbers for Low Speed Idler Gear Assemblies
Model	3508	3512	3516
Industrial	S/N:68Z874	N/A	S/N:71Z324
Marine	S/N:69Z717	N/A	S/N:72Z518
Generator Set	S/N:70Z952	N/A	S/N:73Z768
Gas (Right Side)	S/N:1313	S/N:4KC567	S/N:3RC1113
	S/N:2JF325	S/N:5JD22	S/N:8LD28
	S/N:9TG56	S/N:7NJ108	S/N:4EK510
Gas (Left Side)	S/N:2JF344	S/N:4KC640	S/N:3RC1201
	S/N:9TG123	S/N:5JD30	S/N:8LD38
	N/A	S/N:7NJ221	S/N:4EK1096

The second stage was the release of the new bearing sleeves on all adapter assemblies. All 3500 Engines that were manufactured after May 1996were built with the new bearing sleeve on the front adapter assemblies.

The third stage was the release of the new bearing sleeve on all the high-speed idler gear assemblies that were manufactured after May 1997. The serial number ranges for this change are shown in Table 20.

Table 20

Effective Serial Numbers for High-Speed Adapter Assemblies
Model	3508	3512	3516
Industrial	S/N:95Y1019	S/N:49Y836	S/N:27Z776
Marine	S/N:96Y1731	S/N:50Y1519	S/N:29Z1235
	S/N:7SM85	S/N:4TN101	S/N:4MJ177
	S/N:2BM123	S/N:7HM176	S/N:8KN156
	N/A	S/N:8EM264	S/N:8CN146
Marine Auxiliary	S/N:3DM94	N/A	S/N:9AN122
Generator Set	S/N:23Z6906	S/N:24Z8021	S/N:25Z5597
	S/N:6PN302	S/N:8RM216	S/N:4XF678
	S/N:4GM224	S/N:6WN142	S/N:5SJ547
	N/A	N/A	S/N:7RN473
	N/A	N/A	S/N:6HN162
Locomotive	S/N:6TJ14	S/N:2WK76	S/N:9KF104
Vehicular	S/N:97Y718	S/N:51Y761	S/N:28Z649
Petroleum	N/A	S/N:1LM142	N/A
Gas	S/N:2JF349	S/N:4KC646	S/N:3RC1228
	S/N:9TG148	S/N:7NJ303	S/N:4EK1352
	N/A	N/A	S/N:5PN35
D11N	S/N:99W3520	N/A	N/A
776B
777B
D11R	S/N:7YG2092	N/A	N/A
5130
776C
777C
D11R	S/N:2GR744	N/A	N/A
992G
776D
777D
789	N/A	N/A	S/N:54Z1170
793
994
789B	N/A	N/A	S/N:2PK1455
793B
5230
793C	N/A	N/A	S/N:7TR402
994G

Table 21

Front Gear Train
Item	Part Number	Description	Option 1	Option 2	Option 3
1	144-8263	Idler Gear Assembly(1)	144-8263	N/A	N/A
	7E-0274		144-8263	N/A	N/A
	111-8145		144-8263	N/A	N/A
	116-3242		116-3242	N/A	N/A
	2W-7321		116-3242	N/A	N/A
	2W-0548		153-1243	N/A	N/A
2	140-9597	Bearing Sleeve	N/A	140-9597	7N-5243
	7N-5243		N/A	140-9597	7N-5243
	116-1365		N/A	116-1365	8N-5301
	8N-5301		N/A	116-1365	8N-5301
3	4P-0668	Adapter Assembly(2)	4P-0668	N/A	N/A
	7C-4164		7C-4164	N/A	N/A
	7C-4165		7C-4165	N/A	N/A
	7E-6748		7E-6748	N/A	N/A
	7N-5245		7N-5245	N/A	N/A
	7N-5263		7N-5263	N/A	N/A
	7N-5279		7N-5279	N/A	N/A
	8N-8210		8N-8210	N/A	N/A
	107-0779		107-0779	N/A	N/A
	107-7362		107-7362	N/A	N/A
4	127-5400	Bearing Sleeve	N/A	127-5400	N/A
	7N-5244		N/A	127-5400	N/A
	2S-7056		N/A	N/A	2S-7056

(1)	Idler gear assemblies come with bearing sleeves that are installed and machined.
(2)	Adapter assemblies come with bearing sleeves that are installed.

Table 21 shows the new part numbers for the idler gear and adapter assembly and the former part numbers for the idler gear and adapter assembly.

Note: All affected adapter assemblies are listed in table 21.

Reconditioning the Components of the Front Gear Train

Three options are available when the idler gear and adapter assembly in the front gear train are being reconditioned.

1. Replace the idler gears and adapters with new parts.

2. Use the original gears and/or adapters with new high strength bearing sleeves.

3. Use the original gears with new bearing sleeves that are medium strength .

The required parts for the rework vary depending on the option that is used to recondition the gear train. Table 21 shows the required parts for each particular option for rework.

Option 1

If idler gear (4) and adapter assembly (1) are replaced with new parts, no further rework is required. The new parts will have the new high strength bearing sleeve that will be installed, and the idler gears will be machined for the finish.

Option 2

If original idler gear (4) and/or adapter (1) is reused, new high strength bearing sleeves (2 and 3) must be pressed into the gear or the adapter. Idler gear assemblies must then be machined. Refer to the section: "Sleeve Installation and Machining Procedure" within this document. No machining for the finish is required for the adapter assembly.

Show/hide table

NOTICE
If the required clearance is not maintained, the bearing sleeve could fail and cause engine damage.

Note: Before installing the gear, make sure that the clearance between the bearing sleeve and the mating shaft meets the required specifications. High-speed idler gears must have 0.12 ± 0.03 mm (0.005 ± 0.001 inch) clearance between the bearing sleeve and the shaft. Low speed idler gears must have 0.09 ± 0.03 mm (0.004 ± 0.001 inch) clearance. Prior to machining the bearing sleeve, measure the shaft and maintain the required clearance.

Option 3

Original idler gear (4) and new bearing sleeves that are medium strength (2) and (3) with the overlay that is lead tin can be used if there is no evidence of bearing cavitation or fatigue. If the procedure for machining for the finish cannot be completed on the bearing that is high strength, use the bearing sleeve that is medium strength. After the bearing sleeves that are medium strength are installed, no machining is required.

Sleeve Installation and Machining Procedure

When bearing sleeves are replaced, use the installation and the removal procedure in the appropriate Service Manual. The same removal procedure for the former bearing sleeves is used for new bearings.

The specifications in the Table 22 are for installation and the machining of the inside diameter of the new bearing sleeves.

1. When an idler gear assembly (4) is reconditioned, the bearing sleeve (3) is installed into the gear to depth (C).

2. Machine by honing the inside diameter to the dimension (A)

Illustration 83	g01509263
The illustration shows items for the bearing sleeve in the idler gear assembly. Refer to Table 22 for identification of the items and dimensions.

Table 22

Specifications for Bearing Sleeve
Dimension	Description
(A)	90.000 ± 0.010 mm (3.5433 ± 0.0004 inch)(1)(2)
	105.970 ± 0.010 mm (4.1720 ± 0.0004 inch)(3)(2)
(B)	The surface of the gear must be square with the bore within 0.05 mm (0.002 inch).
(C)	2.3 ± 0.5 mm (0.09 ± 0.02 inch)
(D)	Pitch diameter must be concentric with a total indicator reading(TIR) of 0.15 mm (0.006 inch) or less.

(1)	High-speed idler gears.
(2)	The surface texture of the inside diameter must be 0.8 micro meter (31.50 micro inch).
(3)	Low speed idler gears.

3500 Rear Gear Train

Table 23

3500 Rear Gear Train
				New Part Numbers
Quantity	Former Part Number	Description	Replace As Needed	Option 1	Option 2	Option 3	Option 4
1	7E-5324	Ring	7E-5324	N/A	N/A	N/A	N/A
2	4W-4793(2)	Camshaft Drive Gear	N/A	7E-3897(1)	N/A	N/A	N/A
	7E-3897			7E-3897(1)	N/A	N/A	N/A
	100-6518			100-6518	N/A	N/A	N/A
	101-1369			101-1369	N/A	N/A	N/A
1-2	101-0242			101-0242	N/A	N/A	N/A
2	7N-5257(2)	Idler Gear Assembly(3)	N/A	4P-5440	N/A	N/A	112-1554
	7E-3894(2)			4P-5440	N/A	N/A	112-1554
	4P-5440			4P-5440	N/A	N/A	112-1554
	115-5281			115-5281	N/A	N/A	121-4749
	112-1554			112-1554	N/A	N/A	N/A
	101-1364			101-1364	N/A	N/A	N/A
	121-4749			121-4749	N/A	N/A	N/A
2	7N-5258	Bearing Sleeve(3)	N/A	N/A	125-9750	125-9750	N/A
	4P-5439(2)			N/A	125-9750	125-9750	N/A
	125-9750			N/A	125-9750	125-9750	N/A
	115-5283			N/A	15-5283	15-5283	N/A
	101-1374(2)			N/A	125-9751	125-9751	N/A
	125-9751			N/A	125-9751	125-9751	N/A
	121-4750			N/A	121-4750	121-4750	N/A
2	1N-3986(4)	Thrust Washer	N/A	4P-5091	4P-5091	4P-5091	101-1368
	4P-5091			4P-5091	4P-5091	4P-5091	101-1368
	101-2983			101-2983	101-2983	101-2983	101-1368
	101-1368			101-1368	101-1368	101-1368	N/A
4	0S-1595	Bolt	0S-1595	N/A	N/A	N/A	N/A
1	4W-4998	Shaft of the Cluster Gear(5)(6)	N/A	4P-5437	4P-5437	N/A	N/A
	4W-5014			4P-5456	4P-5456	N/A	N/A
	4P-5437			4P-5437	4P-5437	N/A	N/A
	4P-5456			4P-5456	4P-5456	N/A	N/A
	101-1366			101-1366	101-1366	N/A	N/A
	101-1378			101-1378	101-1378	N/A	N/A
2	1N-4054(2)	Idler Gear Shaft(3)	N/A	4P-5090	4P-5090	N/A	112-1552
	4P-5090			4P-5090	4P-5090	N/A	112-1552
	101-2982			101-2982	101-2982	N/A	112-1552
	112-1552			112-1552	112-1552	N/A	N/A
	101-1367			101-1367	101-1367	N/A	N/A
4	1A-5822	Bolt	1B-4367	1B-4367	1B-4367	1B-4367	1B-4367
	1B-4367
2	8S-2331	Bolt	8S-2331	N/A	N/A	N/A	8S-2331
1	7N-6983	Bearing Sleeve(6)	N/A	N/A	4P-5438	4P-5438	4P-5438
	7N-2864			N/A	4P-5460	4P-5460	4P-5460
	4P-5438			N/A	4P-5438	4P-5438	4P-5438
	4P-5460			N/A	4P-5460	4P-5460	4P-5460
	115-5279			N/A	115-5279	115-5279	115-5279
	101-1372			N/A	101-1372	101-1372	N/A
2	1D-4609	Bolt	9X-8887	9X-8887	9X-8887	9X-8887	9X-8887
	9X-8887			N/A	N/A	N/A	N/A
2	5P-8246	Hard Washer	5P-8246	N/A	N/A	N/A	N/A
1	7E-8777(2)	Cluster Gear Assembly(5)(6)	N/A	4P-5459	N/A	N/A	N/A
	7E-3891(2)			4P-5457	N/A	N/A	N/A
	7E-8779(2)			107-2477	N/A	N/A	N/A
	7E-8781(2)			4P-5458	N/A	N/A	N/A
	4P-5459			4P-5459	N/A	N/A	N/A
	4P-5457			4P-5457	N/A	N/A	N/A
	4P-5441(2)			107-2477	N/A	N/A	N/A
	4P-5458			4P-5458	N/A	N/A	N/A
	107-2477			107-2477	N/A	N/A	N/A
	115-5277			115-5277	N/A	N/A	N/A
	101-1363			101-1363	N/A	N/A	N/A
	101-1381(2)			114-3372	N/A	N/A	N/A
	114-3372			114-3372	N/A	N/A	N/A
	101-1377			101-1377	N/A	N/A	N/A
1	7N-5254	Thrust Plate	N/A	101-1365	101-1365	101-1365	101-1365
	101-1365			101-1365	101-1365	101-1365	101-1365
2	4W-4586	Plate	4W-4586	N/A	N/A	N/A	N/A
4	0L-1351	Bolt	N/A	0L-1351	N/A	N/A	N/A
12	3S-1307	Bolt	3S-1307	N/A	N/A	N/A	N/A
1	2W-2895	Crankshaft Gear	2W-2895	N/A	N/A	N/A	N/A
	101-1370		101-1370	N/A	N/A	N/A	N/A

(1)	The 7E-3897 Camshaft Drive Gear can be directly replaced with a 100-6518 Camshaft Drive Gear in any 3500 Engine application. However, the 100-6518 Camshaft Drive Gear must be used in all 3516 S/N:4MJ34 Marine Engines unless 8 pitch gears are used.
(2)	Canceled
(3)	New idler gear assemblies (4) are ready for installation. Former idler shafts (9) and new bearing sleeves (5) cannot be used together unless both parts are reconditioned. If the bearing sleeve is serviced separately, refer to the "All Camshaft Idler Gear and Cluster Gear Assemblies" section in this guideline.
(4)	This part is not Canceled.
(5)	New cluster gear assemblies (15) are ready for installation. Former shafts of cluster gears (8) and new bearing sleeve (12) cannot be used together unless both parts are reconditioned. If the sleeve bearing is serviced separately, refer to "All Camshaft Idler Gear and Cluster Gear Assemblies" section in this Guideline.
(6)	Order the part number that is specific to the engine application.

During rebuild, refer to Table 23 to determine which parts must be replaced. The parts that are listed in the Replace as Needed column should be checked during each rebuild. The parts that are listed under the column, Option, are the parts that are required for that particular option for rework. Some parts are not common with all engine models. Those parts are the assemblies of the cluster idler gear, the bearing sleeves, and the shafts. For these parts, order the part number that is required for the specific engine model. Not all the parts in the gear group have changed.

Improvements to the Rear Gear Train

Several changes were made to improve the service life and reliability of the rear gear train. These changes include new gears, bearing sleeves, and gear shafts. As a result of reconditioning or replacing existing parts, older engines can gain the same benefits as newer engines.

The following list of improvements is divided into two sections: 3500 and 3500B Changes that affect both series of engines will be discussed in each section.

3500

• New drive gears for the cam, idler gears, and cluster gears are used. The new parts now have a deeper depth of the case of hardened material. The new parts are case carburized.

• A new 100-8310 Rear Gear Gp has been developed. The new rear gear group is a direct replacement for the former 4W-5906 Rear Gear Gp. The new gear group is now effective with all the 3516 marine engines. The serial number 4MJ34 is adapted with the new gear group. The gear group is adaptable to all earlier engines. The new 100-6518 Camshaft Drive Gear that is heavier has increased rotational inertia. This improvement has lowered the mesh torques for gear to gear, which has resulted in an increase of the service life of the gear.

Illustration 84	g06177130
Camshaft Drive Gear. Gear (A) on left shows a cross section of 100-6518 Camshaft Drive Gear. Gear (B) on right shows 7E-3897 Camshaft Drive Gear.

• New 8 pitch gears are available for the small cluster gear, idler gear, and the camshaft drive gear for 3516-Phase II Marine and Generator Set Engines. The 8 pitch gears can handle more torque than the former 10 pitch gears. This new gear results in increased service life of the gear. This change is not retrofitted to the earlier engines because of a change to the flywheel housing for allowing the larger gears.

• The bearing sleeves in the cluster gears and idler gears have been changed from aluminum bearing sleeves with steel backing to bronze bearing sleeves with steel backing. This change will increase the resistance to fatigue for the bearing.

• The cluster and idler gear shafts are slightly larger in diameter. This change reduces the clearance between the shaft and the sleeve bearings to minimize the wobble of the gear.

• The new shafts for the cluster gear and the idler gear have two smaller oil supply holes instead of one hole with a large diameter. This improvement will provide better distribution of the oil to the bearing sleeve.

• Idler gear shafts have a thicker flange to prevent breakage at the corners of the half flange.

• The bolt pattern and shaft diameter of the idler gear shaft has been changed. The new shaft has a bolt hole pattern with three bolt holes instead of a bolt hole pattern with two bolt holes to secure the idler shaft to the block. The new idler shaft uses three 5/8-11 bolts. The former idler shaft used two 5/8-11 or two 1/2-13 bolts. The shaft diameter has also changed to accept the new bolt hole pattern. 3500 and 3500B cylinder blocks are now common cylinder blocks.

• A new bronze bearing sleeve with a steel backing 125-9751 bearing sleeve has been released with a larger outer diameter to increase the interference fit between the gear and bearing sleeve. This bearing sleeve will result in better retaining of the bearing sleeve in the camshaft idler gear assembly.

• The interference fit between the small cluster gears and the large cluster gears has been increased. This increase will provide the retention of the joint and will reduce the risk of slippage of the joint of the gear.

• The cylinder block and the idler gear thrust washers have been changed to accept the three bolt hole pattern.

3500B

• With the release of the 3500B, the pitch of the small cluster, idler, and camshaft drive gear has been changed from 10 to 8. The reduced pitch provides better carrying capability for torque.

• The interference fit between the small cluster gears and the large cluster gears has been increased. This increase will provide the retention of the joint and will reduce the risk of slippage of the joint of the gear.

The following sections in this guideline describe the specifications and procedures to recondition existing parts to take advantage of the listed improvements.

Engines That Were Affected By The Improvements

The improvements to the 3500 Engines came in several stages. The first stage included the replacement of the former gears with the new case carburized gears. The engines and the serial numbers that were affected by this change are listed in Table 24.

The second stage incorporated the introduction of the new bronze bearing sleeves with steel backing, the change in diameter and number of oil feed holes to the cluster and idler shafts, and the change to provide a thicker flange on the idler shaft. Also, the bolts that secure the idler shaft were changed from 1/2-13 to 5/8-11. Table 25 lists the engines that are affected by these changes. Engines that are first listed in the Table 25 include the change to the case carburized gears.

The third stage included the increase in the number of bolts that secure the idler shaft from two bolts to three bolts. Also, a common block was provided for 3500 and 3500B Engines. Refer to Special Instruction, SEHS9826, "Ordering "Series B" Replacement Cylinder Blocks for 3500 Series Engines" for more information. Table 26 lists the engines and the serial numbers that are affected by this change.

The next stage was to release 8 pitch gears for 3516-Phase II Marine and Generator Set Engines. The effective serial numbers for the affected engines are listed in Table 27.

Next, the interference fit between the idler gear and bearing sleeve was increased. Table 28 lists the engines and the serial numbers that are affected by this change.

Next, the interference fit between the small cluster gear and the large cluster gear was increased. The effective serial numbers for the affected engines are listed in Table 29.

Note: Not all serial numbers are listed in Table 29. All engines that were manufactured after June 1995contain cluster gears with an increased interference fit.

Table 24

Effective Serial Numbers for Case Carburized Gears in Rear Gear Trains (Camshaft Drive)
Model	3508	3512	3516
Industrial	N/A	S/N:65Z715	S/N:71Z297
Marine	N/A	S/N:66Z423	S/N:72Z415
Generator Set (low speed)	N/A	S/N:67Z794	S/N:73Z405
D11N	S/N:99W1942	N/A	N/A
776B
777B
789	N/A	S/N:54Z661	N/A

Table 25

Effective Serial Numbers for Changes to the Cluster and Shaft of the Idler Bearing Sleeve
Model	3508	3512	3516
Industrial	S/N:95Y791	S/N:49Y606	S/N:27Z693
Industrial	S/N:68Z776	S/N:65Z724	S/N:71Z302
Marine	S/N:96Y1147	S/N:50Y948	S/N:29Z967 S/N:4MJ34 S/N:5MJ33
Marine	S/N:69Z562	S/N:66Z434	S/N:72Z427
Generator Set	S/N:23Z3671 S/N:1ZF593	S/N:24Z3920 S/N:3YF604	S/N:25Z226 S/N:4XF382
Generator Set (low speed)	S/N:70Z775	N/A	S/N:73Z463
Locomotive	N/A	N/A	S/N:9KF56
Vehicular	S/N:97Y673	S/N:51Y629	S/N:28Z625
D11N	S/N:99W2752	N/A	N/A
776B
777B
785	N/A	S/N:96Z740	N/A
789	N/A	S/N:54Z719	N/A

Table 26

Effective Serial Numbers for Idler Shafts with Three Bolt Hole Patterns
Model	3508	3512	3516
Industrial	S/N:95Y942	S/N:49Y741	S/N:27Z759
Industrial	S/N:68Z838	S/N:65Z805	S/N:71Z318
Marine	S/N:96Y1485	S/N:50Y1317	S/N:29Z1120 S/N:4MJ162 S/N:5MJ33
Marine	S/N:69Z664	S/N:66Z579	S/N:72Z427
Generator Set	S/N:23Z5701	S/N:24Z6028	S/N:25Z4283 S/N:4XF572 S/N:5SJ289
Generator Set (low speed)	S/N:70Z887	S/N:67Z1185	S/N:73Z682
Locomotive	S/N:6TJ12	S/N:2WK40	S/N:9KF80
Vehicular	S/N:97Y688	S/N:51Y731	S/N:28Z635
Petroleum	N/A	S/N:1LM48	N/A
Gas	S/N:2JF302 S/N:9TG27	S/N:4KC557 S/N:5JD19	S/N:3RC1072 S/N:4EK374
D11N	S/N:99W3447	N/A	N/A
776B
777B
D11R	S/N:7YG959	N/A	N/A
5130
776C
777C
785	N/A	S/N:96Z912	N/A
785B	N/A	N/A	S/N:4WJ535
789	N/A	S/N:54Z1069	N/A
793
994
789B	N/A	S/N:2PK679	N/A
793B
5230

Table 27

Effective Serial Numbers for the Introduction of 8 Pitch Gears
Model	3508	3512	3516
Marine	N/A	N/A	S/N:4MJ150
Generator Set	N/A	N/A	S/N:5SJ162 S/N:4XF460

Table 28

Effective Serial Numbers for 125-9751 Bearing Sleeve
Model	3508	3512	3516
Industrial	S/N:95Y968	S/N:49Y760	S/N:27Z762
Industrial	S/N:68Z843	S/N:65Z831	S/N:71Z318
Marine	S/N:96Y1563	S/N:50Y1383	S/N:29Z1168 S/N:5MJ33
Marine	S/N:69Z685	S/N:66Z613	S/N:72Z481
Generator Set	S/N:23Z6191 S/N:8TL3	S/N:24Z6689	S/N:25Z4726 S/N:4XF606
Generator Set (low speed)	S/N:70Z925	S/N:67Z1286	S/N:73Z701
Locomotive	S/N:6TJ14	N/A	S/N:9KF103 S/N:5PN35
Vehicular	S/N:97Y697	S/N:51Y740	S/N:28Z637
Petroleum	N/A	S/N:1LM67	N/A
Gas	S/N:2JF330 S/N:9TG67 S/N:4WD13	S/N:4KC593 S/N:5JD23 S/N:7NJ133	S/N:3RC1126 S/N:4EK600 S/N:8LD28
D11N	S/N:99W3487	N/A	N/A
776B
777B
D11R	S/N:7YG1438	N/A	N/A
5130
776C
777C
785	N/A	S/N:96Z913	N/A
785B	N/A	S/N:4WJ643	N/A
789	N/A	N/A	S/N:54Z1117
793
994
789B	N/A	N/A	S/N:2PK906
793B
5230

Table 29

Effective Serial Numbers for the Increased Interference Fit Cluster Gear.
Model	3508	3512	3516
Marine	N/A	N/A	S/N:8KN68
Generator Set	N/A	N/A	S/N:5SJ353 S/N:4XF593
Locomotive	N/A	N/A	S/N:5PN35
Gas	N/A	S/N:5JD20 S/N:7NJ73	S/N:4EK371 S/N:8LD28
785B	N/A	S/N:4WJ545	N/A
789B	N/A	N/A	S/N:2PK680
793B
5230

Reconditioning the Components of the Rear Gear Train

Four options are available for reconditioning the drive group for the rear gear train. These options are listed as following.

1. Replace all the parts in the gear train.

2. Use the original gears with new bronze bearing sleeves and shafts.

3. Use the original shafts and gears with new bronze bearing sleeves.

4. This option is for the required rework, when a replacement block is used.

The parts that are required for the rework may vary depending on the option that is used to recondition the gear train. Table 23 shows the part number, under the column, Option, which is required for that particular option for rework. Each option is explained in more detail below.

Option 1

If all the gears and the shafts in the rear gear train are replaced, then modifying or reworking of the bolt holes which retain the idler gear shaft (8) is the only action that is needed. If the current engine block has 5/8-11 threaded holes or a pattern of three bolt holes, then no modification is necessary. If the holes are 1/2-13, then the holes must be drilled and tapped according to the rework procedure. "Rework of Bolt Holes in Cylinder Block" in this guideline.

Option 2

If the original gears are used again, then new bronze bearing sleeves must be pressed into the gear and machined to a finish. The "All Camshaft Idler Gear and Cluster Gear Assemblies" section in this guideline provides a procedure for this operation. Also, check the bolt holes in the cylinder block that retain idler gear shaft (9) to determine if the bolt holes should be reworked.

Option 3

If the original shafts and gears are used again with the new bronze bearing sleeves, then the new bearing sleeves must be pressed into the gear and machined to a finish.

Idler gear shafts (8) and the shaft for the cluster gear (8) must also be reworked for a second oil hole, if necessary. This rework procedure is contained in the "Reworking Idler and Cluster Gear Shafts" section.

Option 4

If the original cylinder block has two 1/2-13 or two 5/8-11 tapped holes for the shaft of the rear camshaft idler gear and the replacement block has three tapped holes, new idler gears (3) and idler gear shafts (8) are required. The original cluster gear (14) and the shaft of the cluster gear (7) can be used again. If the original cluster gear assembly is used again, then new bronze bearing sleeves must be pressed into the gear and machined to a finish. The "All Camshaft Idler Gear and Cluster Gear Assemblies" section provides a procedure for this operation. The shaft of the cluster gear (8) must also be reworked for a second oil hole, if necessary.

Note: Maintain the correct clearance between the shaft and idler gear and cluster gear. The clearance in diameter between the shaft and idler gear is 0.060 ± 0.020 mm (0.0024 ± 0.0008 inch). The clearance in diameter between the shaft and cluster gear is 0.070 ± 0.020 mm (0.0028 ± 0.0008 inch). Prior to machining the bearing sleeve, take a measurement from the shaft and maintain the above clearance.

Rework of Bolt Holes in Cylinder Block

One improvement to the gear group was the increase of the size of the bolts (9) that retain the idler shaft to the cylinder block. This rework procedure contains the tool list, instructions, and dimensions for drilling and tapping the bolt holes for the idler shaft.

Reconditioning the bolt holes of the idler shaft in the block is an acceptable repair, and will cost less than replacing the cylinder block.

Tooling

Illustration 85	g02515196
The illustration shows the tools that are required for the rework procedure. Refer to Table 30 for the part numbers and the description.

Table 30

Required Tooling
Item	Quantity	Part Number	Description
N/A	1	4C-9992(2)	Pilot
(20)	1	1P-3048	Tap Wrench
(21)	1	9U-5034(2)	Tap for Bottoming 5/8-11thd.
(22)	2	1A-5822(1)	Bolt, 1/2-13 thd., 69.9 mm (2.75 inch)
(23)	1	1B-4367(2)	Bolt, 5/8-11 thd, 69.9 mm (2.75 inch) long.
(24)	1	4C-9993(2)	Guide Plate
(25)	2	6V-4857	Lock Screw
(26)	1	4C-9997(2)	Drill Bushing 16.13 mm (0.635 inch) (pilot for 15.88 mm (0.625 inch) tap)
(27)	1	4C-9996(2)	Drill Bushing 15.88 mm (0.625 inch)
(28)	1	4C-9995(2)	Drill Bushing 13.49 mm (0.531 inch)
(29)	1	4C-9994(2)	Drill Bushing 12.70 mm (0.500 inch)
(30)	1	9U-5033(2)	Core Drill, four fluted 13.49 mm (0.531 inch)

(1)	Bolts that are used for installing the original idler shaft
(2)	This tool is included in the 4C-9991 Tool Group for Retrofitting of Idler Shaft.

Procedure

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Illustration 86	g02515277
The illustration shows the installation of the guide plate onto the cylinder block. (24) Guide Plate (28) Drill Bushing 13.49 mm (0.531 inch) (29) Drill Bushing 12.70 mm (0.500 inch)

1. Install bearing sleeve (28) and (29) into guide plate (24).
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   Illustration 87	g02515296
   The illustration shows the installed guide plate (24). (22) Bolt, 1/2-13 thd., 69.9 mm (2.75 inch) (24) Guide Plate (28) Drill Bushing 13.49 mm (0.531 inch) (29) Drill Bushing 12.70 mm (0.500 inch)

2. Mount the guide plate (24) with two 1A-5822 Bolts (22) that were used to retain the idler shaft. Using both bolts will correctly position the guide plate. Tighten the bolts to 105 ± 20 N·m (75.0 ± 15.0 lb ft). After the bolts are tight, remove the bolt from bearing sleeve (28).
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   Illustration 88	g01477933
   Use a heavy-duty drill with variable speed.

3. Drill the first hole with core drill (30) with a heavy-duty drill with variable speed. For best results and longest life of the drill, run the drill at approximately 440 rpm. The hole is drilled until the core drill contacts the bottom of the original hole. The speed of the motor of the drill will increase when the drill contacts the bottom of the hole.

4. Clean the debris from the drilled hole.
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   Illustration 89	g02515336
   Installing the guide bushing for tapping (26) Drill Bushing 16.13 mm (0.635 inch) (pilot for 15.88 mm (0.625 inch) tap) (28) Drill Bushing 13.49 mm (0.531 inch)

5. Remove 13.49 mm (0.531 inch) bearing sleeve (28), and install 16.13 mm (0.635 inch) bearing sleeve (26). Bearing Sleeve (26) is used as a pilot for the 5/8-11 tap.
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   Illustration 90	g02515359
   Use a fluid for tapping during this process. (20) Tap Wrench (21) Tap for Bottoming 5/8-11 thd.

6. Tap the drilled hole with the 5/8-11 tap for bottoming (21), until the tap comes into contact with the bottom of the hole. Use liberal amounts of fluid for tapping during the process. When the process is complete, remove the tap, and clean the hole.

   A recommended fluid for tapping is TAP MAGIC. For the address of a local supplier, contact the following.

   TAP MAGIC
   Steco Corporation
   P.O. Box 2238
   Little Rock, AR 72203 (USA)
   http://www.steco.com/
   
   Show/hide table

   Illustration 91	g02515376
   Install a new 5/8-11 bolt, and rework the remaining hole. (23) Bolt, 5/8-11 thd. 69.9 mm (2.75 inch) long. (27) Drill Bushing 15.88 mm (0.625 inch) (28) Drill Bushing 13.49 mm (0.531 inch)

7. Remove bearing sleeve (26), and install 15.88 mm (0.625 inch) bearing sleeve (27) into the guide plate. Install 1B-4367 Bolt (23), and tighten to 105 ± 20 N·m (75.0 ± 15.0 lb ft).

8. Remove 1A-5822 Bolt (22), and drill bushing (29). Install new drill bushing (28).

9. Repeat Steps 3 through 6.

10. After the second hole is drilled and tapped, remove guide plate (24). Remove any burrs or sharp edges that would prevent the idler shaft from correctly seating against the cylinder block.

11. Install the idler shaft and thrust washer. Refer to "Bolt Torque" in the next section for tightening specifications.

Bolt Torque

Tighten the bolts (9) that are retaining the idler gear assembly (3) to the proper torque.

Illustration 92	g06177158
The illustration shows locations of the bolts and the idler shafts of the rear gear trains for 3512 and 3516 Engines. (3) Idler Gear Shaft (9) Bolt. (8) Idler Shaft

Earlier rear gear trains used 1/2-13 1A-5822 Bolts which were tightened to 135 ± 15 N·m (100.0 ± 11.0 lb ft).

Current rear gear trains use 5/8-11 1B-4367 Bolts which are tightened to 240 ± 20 N·m (176.0 ± 15.0 lb ft). These bolts are used in newer models, or rear groups which were salvaged by tapping the holes to 5/8-11.

Note: Add this new information on bolt tightening to the module for specifications and the module for Disassembly and Assembly in the appropriate Service Manuals.

Reworking Idler and Cluster Gear Shafts

This procedure is for reworking idler gear shaft (9) and the shaft of the cluster gear (8). If the original shafts ( 1N-4054 Idler Shaft, 4W-4998 Gear Shaft, or 4W-5014 Idler Shaft) are used again, then the shafts must be reworked to provide a second oil hole. This oil hole is made by extending the current oil hole through to the other side of the shaft.

The oil hole of the shaft can be drilled on a small drill press. The shaft must be clamped in a vise. The speed of the spindle should be approximately 440 rpm. Illustrations 93 and 94 show the new style of shafts which have through oil holes. Use the following procedure to add the second oil hole.

Illustration 93	g01477940
The new idler shaft is shown on the left. The old idler shaft is shown on the right.

Illustration 94	g01477942
The new shaft of the cluster gear is shown on the left. The old shaft of the cluster gear is shown on the right.

1. Clamp the shaft in a vise.

   Note: Do not use a solid carbide drill bit.

2. Use the existing oil hole as a pilot to drill the new oil hole. Use a 5.94 mm (0.234 inch) carbide tipped drill bit, and drill approximately 1.5 mm (0.06 inch) into the shaft.

3. Remove the carbide drill bit, and change to a 5.94 mm (0.234 inch) cobalt drill bit. Drill through the shaft. Use liberal amounts of cutting fluid to cool the drill bit.

4. Chamfer the oil hole with a carbide burr to remove any burrs. If burrs are not removed, then burrs can damage the bearing sleeves.

All Camshaft Idler Gear and Cluster Gear Assemblies

When bearing sleeves are replaced, use the installation and the removal procedure in the Service Manual. The same procedure is used for the removal of the bearings for both the former style and the new style. Former idler gears and idler shafts CANNOT be mixed with new idler gear assemblies and idler shafts. If a new idler gear assembly is used, then the assembly should be installed with a new idler shaft.

1. During the reconditioning of the cluster gear assembly (15), install the bearing sleeve (12) into the gear (15) to the depth (B). During reconditioning of the idler gear assembly (4), install the bearing sleeve (5) into the gear (4) to the depth (E).
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   Illustration 95	g06177163
   The illustration shows an assembly of a balancer gear. Refer to Table 31 for reference dimensions.

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   Illustration 96	g06177165
   The illustration shows an idler gear assembly. Refer to Table 31 for reference dimensions.

2. After the bearing sleeve is installed, then hone the inside diameter to dimension (A) for the cluster gear or the idler gear.

Table 31

Specifications for Installing and Machining Bearing Sleeves
Item	Description
(A)	75.060 ± 0.010 mm (2.9550 ± 0.0004 inch)(1) 81.060 ± 0.010 mm (3.1913 ± 0.0004 inch)(1)(2)
(B)	1.5 ± 0.5 mm (0.06 ± 0.02 inch)
(C)	Pitch diameter must be concentric with a total indicator reading (TIR) of 0.15 mm (0.006 inch)or less.
(D)	The surface of the gear must be square with the bore within 0.05 mm (0.002 inch).
(E)	1.00 ± 0.25 mm (0.040 ± 0.0010 inch)
(F)	Pitch diameter must be concentric with a total indicator reading (TIR) of 0.12 mm (0.005 inch) or less.

(1)	The surface texture of the inside diameter must be 0.8 µm (32 µinch).
(2)	This dimension is for the inside diameter of the bearing sleeve for 112-1554 Idler Gear As, 101-1364 Idler Gear As, and 121-4749 Gear As for use with 125-9751 Bearing Sleeve and 121-4750 Bearing Sleeve.

Idler Gear Bearing Sleeve Machining and Salvage

The process and tool recommendations to machine bronze-faced, steel-backed replacement bearing sleeve for stub shaft mounted idler gears on Cat engines. This procedure is a robust and repeatable process to salvage idler gears. If the procedures found in this guideline are followed, bearing sleeves can successfully be pressed and machined into idler gears.

It is critical to the gear assembly that the surface texture and diameter are checked 100% and are within specifications.

When setting up and locating the gear in the machine, it is critical that the Pitchline TIR (process datum location), and Perpendicular TIR are checked. The locating gage pins for the pitch line must be used (refer to Table 32 and 33). Failure to align the bearing sleeve for machining and check required machining specifications, can cause gear train failures.

• The surface texture on the inside diameter after machining shall not exceed 0.80 µm (31.49606 µinch) Ra on any bearing sleeve.

• Shafts must also meet the specification for reuse.

• Machine the bearing sleeve to print tolerance found in Table 32 and 33.

• The machining process must use the pitch line of the gear for locating.

Specifications

The surface texture on the inside diameter after machining shall not exceed 0.80 µm (31.49606 µinch) Ra on any bearing sleeve in Table 32 and 33.

Table 32

Idler Gear and Shaft Specifications for Bronze Backed Bearing Sleeve
Gear As Part Number	Bearing Sleeve Part Number	Nominal Machined Bearing Sleeve I.D.	Pitchline TIR(1)	Max Gear Face TIR(2)	Gear Gage Pin Size(s)	Bearing Sleeve Depth in the Gear
4P-3130 130-5478 512-3024	9Y-1539 432-4362	150.002 ± 0.002 mm (5.90558 ± 0.00008 inch)	N/A	N/A	10 mm (0.39370 inch)	3 ± 0.5 mm (0.11811 ± 0.01968 inch)
4P-5440	125-9750	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.12 mm (0.00472 inch)	0.05 mm (0.00197 inch)	4.7625 mm (0.18750 inch)	1 ± 0.25 mm (0.03937 ± 0.00984 inch)
4P-5457	4P-5460	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.05 mm (0.00197 inch)	4.7625 mm (0.18750 inch) and the Gear 2-gage pin size is 6.35 mm (0.25000 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
4P-5458	4P-5460	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.05 mm (0.00197 inch)	4.7625 mm (0.18750 inch) and the Gear 2-gage pin size is 6.35 mm (0.25000 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
4P-5459	4P-5438	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.05 mm (0.00197 inch)	5 mm (0.19685 inch) and the Gear 2-gage pin size is 6.35 mm (0.25000 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
101-1363	101-1372	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.05 mm (0.00197 inch)	6 mm (0.23622 inch) and the Gear 2-gage pin size is 5 mm (0.19685 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
101-1364	125-9751	81.06 ± 0.01 mm (3.19133 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.1 mm (0.0039 inch)	6 mm (0.23622 inch)	1 ± 0.25 mm (0.03937 ± 0.00984 inch)
101-1377	4P-5460	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch)	N/A	6 mm (0.23622 inch) and the Gear 2-gage pin size is 5 mm (0.19685 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
107-2477	4P-5438	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.05 mm (0.00197 inch)	5 mm (0.19685 inch) and the Gear 2-gage pin size is 6.35 mm (0.25000 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
112-1554	125-9751	81.06 ± 0.01 mm (3.19133 ± 0.00039 inch)	0.12 mm (0.00472 inch)	0.05 mm (0.00197 inch)	4 mm (0.15748 inch)	1 ± 0.25 mm (0.03937 ± 0.00984 inch)
114-3372	101-1372	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.05 mm (0.00197 inch)	6 mm (0.23622 inch) and the Gear 2-gage pin size is 5 mm (0.19685 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
127-4628	125-9751	81.06 ± 0.01 mm (3.19133 ± 0.00039 inch)	0.12 mm (0.00472 inch)	0.1 mm (0.0039 inch)	8 mm (0.31496 inch)	1 ± 0.25 mm (0.03937 ± 0.00984 inch)
136-3277	101-1372	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	8 mm (0.31496 inch) and the Gear 2-gage pin size is 12 mm (0.47244 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
149-9107	128-2661 131-7123	63.566 ± 0.013 mm (2.50259 ± 0.00051 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	5 mm (0.19685 inch) and Gear 2 is 6 mm (0.23622 inch)	2.8 ± 0.5 mm (0.11024 ± 0.01968 inch)
175-5197	125-9751	81.06 ± 0.01 mm (3.19133 ± 0.00039 inch)	0.12 mm (0.00472 inch)	0.1 mm (0.0039 inch)	6 mm (0.23622 inch)	1 ± 0.25 mm (0.03937 ± 0.00984 inch)
175-5200	101-1372	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	6 mm (0.23622 inch) and the Gear 2-gage pin size is 5 mm (0.19685 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
185-1495 331-6185	224-9664	71.035 ± 0.013 mm (2.79665 ± 0.00051 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	8 mm (0.31496 inch) and the Gear 2-gage pin size is 10 mm (0.39370 inch)	2.5 ± 0.5 mm (0.09843 ± 0.01968 inch)
185-1497	224-9664	71.035 ± 0.013 mm (2.79665 ± 0.00051 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	8 mm (0.31496 inch)	2.6 ± 0.5 mm (0.10236 ± 0.01968 inch)
187-8979	128-2661 131-7123	63.566 ± 0.013 mm (2.50259 ± 0.00051 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	5 mm (0.19685 inch) and Gear 2-gage pin size is 6 mm (0.23622 inch)	2.8 ± 0.5 mm (0.11024 ± 0.01968 inch)
200-2454	128-2661 131-7123	63.566 ± 0.013 mm (2.50259 ± 0.00051 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	5 mm (0.19685 inch) and Gear 2 is 6 mm (0.23622 inch)	2.8 ± 0.5 mm (0.11024 ± 0.01968 inch)
206-4225	209-8621	88.09 ± 0.013 mm (3.46810 ± 0.00051 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	10 mm (0.39370 inch)	Center the bearing sleeve in the gear
207-8211	209-8621	88.09 ± 0.013 mm (3.46810 ± 0.00051 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	10 mm (0.39370 inch)	Center the bearing sleeve in the gear
226-6036	226-6052	88.09 ± 0.013 mm (3.46810 ± 0.00051 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	8 mm (0.31496 inch) and the Gear 2-gage pin size is 10 mm (0.39370 inch)	3.2 ± 0.5 mm (0.12598 ± 0.01968 inch)
228-5814	209-8621	88.09 ± 0.013 mm (3.46810 ± 0.00051 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	10 mm (0.39370 inch)	3 ± 0.5 mm (0.11811 ± 0.01968 inch)
230-6202	224-9664	71.035 ± 0.013 mm (2.79665 ± 0.00051 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	8 mm (0.31496 inch) and the Gear 2-gage pin size is 4 mm (0.15748 inch)	2.6 ± 0.5 mm (0.10236 ± 0.01968 inch)
243-3008	243-3007	137.91 mm (5.42952 inch)	0.25 mm (0.00984 inch)	0.1 mm (0.0039 inch)	10 mm (0.39370 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
254-5886	254-5887	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	8 mm (0.31496 inch) and the Gear 2 gage pins size is 10 mm (0.39370 inch)	2 ± 0.5 mm (0.07874 ± 0.01968 inch)
261-3133	101-1372	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.05 mm (0.00197 inch)	6 mm (0.23622 inch) and the Gear 2-gage pin size is 5 mm (0.19685 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
261-3137	125-9751	81.06 ± 0.01 mm (3.19133 ± 0.00039 inch)	0.12 mm (0.00472 inch)	0.05 mm (0.00197 inch)	6 mm (0.23622 inch)	1 ± 0.25 mm (0.03937 ± 0.00984 inch)
261-3443	226-6052	88.09 ± 0.013 mm (3.46810 ± 0.00051 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	8 mm (0.31496 inch) and the Gear 2-gage pin size is 10 mm (0.39370 inch)	3.2 ± 0.5 mm (0.12598 ± 0.01968 inch)
261-3445	209-8621	88.09 ± 0.013 mm (3.46810 ± 0.00051 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	10 mm (0.39370 inch)	3 ± 0.5 mm (0.11811 ± 0.01968 inch)
271-5656	128-2661	63.566 ± 0.013 mm (2.50259 ± 0.00051 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	4.7625 mm (0.18750 inch) and the Gear 2-gage pin size is 5 mm (0.19685 inch)	0.38 ± 0.25 mm (0.01496 ± 0.00984 inch)
300-5575	128-2661 131-7123	63.566 ± 0.013 mm (2.50259 ± 0.00051 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.1 mm (0.0039 inch)	4.763 mm (0.18752 inch) and the Gear 2-gage pin size is 5 mm (0.19685 inch)	0.38 ± 0.25 mm (0.01496 ± 0.00984 inch)
307-2402	307-2403	89.965 ± 0.01 mm (3.54192 ± 0.00039 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	10 mm (0.39370 inch)	2.3 ± 0.5 mm (0.09055 ± 0.01968 inch)
310-3177	101-1372	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.05 mm (0.00197 inch)	6 mm (0.23622 inch) and the Gear 2-gage pin size is 5 mm (0.19685 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
312-1676	312-1678	105.98 ± 0.01 mm (4.17243 ± 0.00039 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	10 mm (0.39370 inch)	2.3 ± 0.5 mm (0.09055 ± 0.01968 inch)
312-1677	312-1678	105.98 ± 0.01 mm (4.17243 ± 0.00039 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	8 mm (0.31496 inch)	2.3 ± 0.5 mm (0.09055 ± 0.01968 inch)
320-6198	209-8621	88.09 ± 0.013 mm (3.46810 ± 0.00051 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	10 mm (0.39370 inch)	3 ± 0.5 mm (0.11811 ± 0.01968 inch)
352-9728	128-2661 131-7123	63.566 ± 0.013 mm (2.50259 ± 0.00051 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	6 mm (0.23622 inch) and the Gear 2-gage pin size is 6 mm (0.23622 inch)	2.8 ± 0.5 mm (0.11024 ± 0.01968 inch)
361-8233	128-2661	63.566 ± 0.013 mm (2.50259 ± 0.00051 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	6 mm (0.23622 inch) and the Gear 2-gage pin size is 6 mm (0.23622 inch)	Center the bearing sleeve in the gear
369-9356	125-9751	81.06 ± 0.01 mm (3.19133 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.1 mm (0.0039 inch)	6 mm (0.23622 inch)	1 ± 0.25 mm (0.03937 ± 0.00984 inch)
369-9357	101-1372	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	0.05 mm (0.00197 inch)	6 mm (0.23622 inch) and the Gear 2-gage pin size is 5 mm (0.19685 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
386-2938	101-1372	75.06 ± 0.01 mm (2.95511 ± 0.00039 inch)	0.1 mm (0.0039 inch)	0.1 mm (0.0039 inch)	10 mm (0.39370 inch) and the Gear 2-gage pin size is 8 mm (0.31496 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
417-4615	417-4616	50.857 ± 0.013 mm (2.00224 ± 0.00051 inch)	N/A	0.05 mm (0.00197 inch)	6 mm (0.23622 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
417-4617	417-4618	50.857 ± 0.013 mm (2.00224 ± 0.00051 inch)	N/A	0.05 mm (0.00197 inch)	6 mm (0.23622 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)

(1)	Maximum Total Indicator Runout (TIR) tolerance read at the gage pins as the gear is rotated in the lathe.
(2)	Maximum Total Indicator Runout (TIR) tolerance read on the face of the gear bore as the gear is rotated in the machine.

Note: All the bearing sleeves in Table 32 are Steel Backed Bronze Bearing Sleeves.

Table 33

Idler Gear and Shaft Specifications for Aluminum Backed Bearing Sleeves
Gear As Part Number	Bearing Sleeves Part Number	Nominal Machined Bearing Sleeves I.D.	Pitchline TIR(1)	Max Gear Face TIR(2)	Gear Gage Pin Size(s)	Bearing Sleeve Depth in the Gear
2W-4087	6N-0977	35.034 ± 0.038 mm (1.37929 ± 0.00150 inch)	N/A	N/A	4.7625 mm (0.18750 inch)	1.12 ± 0.25 mm (0.04409 ± 0.00984 inch)
7E-0274 7N-5241 144-8263	7N-5243 140-9597	90.0 ± 0.01 mm (3.54330 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.1 mm (0.0039 inch)	6 mm (0.23622 inch)	2.3 ± 0.5 mm (0.09055 ± 0.01968 inch)
7E-3894 7N-5257	7N-5258 125-9750	75.000 ± 0.055 mm (2.95275 ± 0.00217 inch)	N/A	N/A	4.7625 mm (0.18750 inch)	1.0 ± 0.25 mm (0.03937 ± 0.00984 inch)
7E-8779 7N-6982	7N-6983	75.0 ± 0.053 mm (2.95275 ± 0.00209 inch)	0.15 mm (0.00591 inch) and 0.1 mm (0.0039 inch) for the inside gear	N/A	4.0 mm (0.15748 inch) and Gear 2 is 6.35 mm (0.25000 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
7E-8777 8N-1266	7N-6983	75.000 ± 0.053 mm (2.95275 ± 0.00209 inch)	N/A	N/A	4.7625 mm (0.18750 inch) and Gear 2 is 6.35 mm (0.25000 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01968 inch)
9Y- 3520	7C-7852	55.163 ± 0.041 mm (2.17177 ± 0.00161 inch)	N/A	N/A	6 mm (0.23622 inch)	1.0 ± 0.25 mm (0.03937 ± 0.00984 inch)
2W-7321 8N-5299 116-3242	116-1365	105.97 ± 0.01 mm (4.17204 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.1 mm (0.0039 inch)	5.0 mm (0.19685 inch)	2.3 ± 0.5 mm (0.09055 ± 0.01968 inch)
132-3233	119-3776	69.385 ± 0.013 mm (2.73169 ± 0.00051 inch)	N/A	N/A	6 mm (0.23622 inch)	1.0 ± 0.25 mm (0.03937 ± 0.00984 inch)
133-7086	133-7084	69.205 ± 0.013 mm (2.72460 ± 0.00051 inch)	0.1 mm (0.00394 inch)	0.1 mm (0.00394 inch)	6 mm (0.23622 inch)	1.0 ± 0.25 mm (0.03937 ± 0.00984 inch)
136-3234	136-3244	112.142 ± 0.01 mm (4.41503 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.1 mm (0.0039 inch)	6 mm (0.23622 inch)	2.3 ± 0.5 mm (0.09055 ± 0.01968 inch)
155-2307	116-1365	105.97 ± 0.01 mm (4.17204 ± 0.00039 inch)	0.15 mm (0.00591 inch)	0.1 mm (0.0039 inch)	5.0 mm (0.19685 inch)	2.3 ± 0.5 mm (0.09055 ± 0.01968 inch)
180-3864 512-3006	190-6465	69.95 ± 0.01 mm (2.75393 ± 0.00039 inch)	N/A	N/A	8 mm (0.31496 inch)	2.5 ± 0.5 mm (0.09843 ± 0.01968 inch)
180-3865 512-3008	190-6465	69.95 ± 0.01 mm (2.75393 ± 0.00039 inch)	N/A	N/A	8 mm (0.31496 inch)	2.5 ± 0.5 mm (0.09843 ± 0.01968 inch)
222-3905	133-7084	69.205 ± 0.013 mm (2.72460 ± 0.00051 inch)	0.1 mm (0.00394 inch)	0.1 mm (0.00394 inch)	6 mm (0.23622 inch)	1.0 ± 0.25 mm (0.03937 ± 0.00984 inch)
286-5303	1W-4738	82.527 ± 0.053 mm (3.2491 ± 0.0021 inch)	N/A	N/A	8 mm (0.315 inch)	N/A
296-5412	296-5413	74.075 ± 0.013 mm (2.91633 ± 0.00051 inch)	0.1 mm (0.00394 inch)	0.1 mm (0.00394 inch)	5 mm (0.19685 inch)	1.08 ± 0.25 mm (0.04252 ± 0.00984 inch)
355-5732	140-9597	90.00 ± 0.01 mm (3.543 ± 0.0004 inch)	0.15 mm (0.00591 inch)	0.1 mm (0.0039 inch)	10 mm (0.394 inch)	2.3 ± 0.5 mm (0.09055 ± 0.01968 inch)

(1)	Maximum Total Indicator Runout (TIR) tolerance read at the gage pins as the gear is rotated in the lathe.
(2)	Maximum Total Indicator Runout (TIR) tolerance read on the face of the gear bore as the gear is rotated in the machine.

Note: All the bearing sleeves in Table 33 are Steel Backed Aluminum Bearing Sleeves.

Machining a New Bearing Sleeve

Press in a New Bearing Sleeve

Illustration 97	g03309216
Pressing in a new bearing sleeve. (A) is the fabricated tool used to press in the bearing sleeve accurately.

Illustration 98	g03383297
(A) is an example of a fabricated tool for pressing in bearing sleeves. Notice the lip or edge indicated by the arrows. The lip ensures that the bearing sleeve is centered in the gear. Since a fabricated tool must be made based on Nominal Machined Bearing Sleeve I.D. and the Bearing Sleeve Depth in the Gear, a single fabricated tool will not work for all gear assemblies or bearing sleeves. Refer to Table 33 for the Nominal Machined Bearing Sleeve I.D. and Bearing Sleeve Depth in the Gear Specifications.

Illustration 99	g03382785
Instead of fabricating a tool, you can use a plate or disk to press the bearing sleeve flush to the gear.

Illustration 100	g03383265
After the bearing sleeve is flush with the gear, use a slightly smaller disk that will fit inside the gear to press the bearing sleeve so that it is centered in the gear.

Illustration 101	g03383270
The two disks used to press in a bearing sleeve. (B) is the larger disk used to press the bearing sleeve flush with the gear. (C) is the smaller disk used to center the bearing sleeve in the gear.

Illustration 102	g03383282
If the bearing sleeve has an oil groove. Make SURE that the groove is lined up with the oil groove in the gear.

Insert the new bearing sleeve using a hydraulic press. Ensure that the bearing sleeve is centered and square in the gear bore unless the assembly print of the gear lists a specific depth for the bearing sleeve. Also make sure that the oil passages in the bearing sleeve are lined with the oil slots in the gear.

Note: Verify the depth of the bore in the gear by looking at the assembly print of the gear.

Aligning the Gear

Locate the gear on the pitch line datum using the following procedure. Locating on the pitch line datum provides the most consistent and repeatable true position needed for the bearing sleeve bore. The utilization of the pitch line datum minimizes the compounding errors from multiple machining operations and tolerances.

Note: The locating gage pins for the pitch line must be used (refer to Table 33). Failure to properly align the bearing sleeve for machining and check required machining specifications, can cause gear train failures.

Each type of gear will require the use of a specific gage pin set. The gage pins are readily available commercially but also can be made. Care must be taken to precisely machine these gage pins to specification due to the close tolerances of the gage pin diameters. If these gage pins are to be made, the use of 52100 alloy steel is recommended. These gage pins are Class ZZ and have an allowed deviation of 0.00508 mm (0.00020 inch), geometry of 0.00254 mm (0.00010 inch), and a surface texture of 0.2540 µm (10.000 µin) Ra. Each gage pin must be machined for each individual gear set according to specified dimensions. Refer to Tables 32 and 33 for correct gage pin size.

Illustration 103	g03307317

First rough center the gear on the lathe. If desired, the use of a cone fitting on the tail stock can help with this process.

Illustration 104	g03306717
Hardened gage pins clamped in place under the clamping teeth.

Illustration 105	g03307436
Magnetic gage pins in place around the gears.

To accomplish locating the pitch line datum, use a matched set of hardened gage pins held under the clamping teeth of the cutting machine. Refer to Illustration 104.

An alternative for using clamped gage pins is to use a matched set of magnetic gage pins next to the jaws to attain a pitch line. Refer to Illustration 105.

The diameter of the gage pins used will vary with different gear sizes. Refer to Table 33 for gage pin and gear matching information.

Illustration 106	g03307017

After securing the gear and the correct gage pins, the gear must be aligned for cutting. Take readings on the outer side of the gage pins with a properly affixed dial indicator, refer to Illustration 106. This measurement will ensure that the gear is centered in the machine in relation to the pitch line datum of the gear teeth.

Note: If using magnetic gage pins, take care the magnetic draw of the gage pins does not cause an inaccurate reading of the dial indicator.

Continue to adjust the locating jaws until the reading of the dial indicator is within the tolerance listed in "Max Pitch TIR" within Table 33.

Illustration 107	g03307542

Check the face perpendicularly with the dial indicator, refer to Table 33 for the minimum specifications.

Adjust the surface of the gear until within "Maximum Gear Perpendicular Runout" specification found within Table 33. The gear is now centered by the pitch line and perpendicular to the cutting machine. Recheck the gage pins to ensure that the face adjustment has not compromised the pitch adjustment.

Machining the Gear Bearing Sleeve

Note: If the stub shaft is to be reused, then check the stub shaft prior to machining the bearing sleeve.

The best results for machining the gear bearing sleeve is obtained by using two passes. The first pass will machine the bearing sleeve to within 0.051 mm (0.002 inch) or less. The second and final pass will machine to final size and final surface texture. When done correctly, this two-step procedure will leave an acceptable finish requiring no further attention.

Note: The feed and RPM rates for your individual cutting tool, machine, and gear will vary to achieve the best surface texture. Various cutting tools have been used with different RPM and feed rates to achieve similar results. For example, a Valenite cutter using a TNMP432 insert used at 1800 RPM and a 0.04572 mm (0.0018 inch) feed rate produced similar results as a CNMG432MP insert at 850 RPM and a 0.04064 mm (0.0016 inch) feed rate.

Note: The required specifications for cutting aluminum bearing sleeves are in Section "Machining Aluminum Bearing Sleeves" below.

Illustration 108	g03784239

Using high RPM and slow feed rate will produce the best finish results.

Machining Aluminum Bearing Sleeves

Machining of the aluminum bearing sleeve requires cutting inserts particular to the properties of the metal. Successful trials were conducted using Kennametal insert number TPGT3252HP KC5410. This insert was used along with Kennametal tool boring bar E16STFPR3 KWH. The tooling was used at 900 RPM with a feed-rate of .0019. Generously applied WD-40 was used as a cutting lubricant. The resulting surface texture easily exceeded print specifications noted in the"Specifications" Table. Consult your tool vendor for other tooling that has the same geometry.

Inspection of Gear Bearing Sleeve After Machining

Checking Bearing Sleeve Diameter

Illustration 109	g03310276
Using a dial bore gauge to measure the bearing sleeve bore size

Critical features such as the bore diameter and surface texture must be checked. The use of proper accuracy of the dial bore gauge, such as the one shown in Illustration 109, is necessary for inspecting the bearing sleeve diameter. Refer to Table 33 for diameter specifications. Check the bore diameter at 3-4 different depths to assure there is no taper. Rotate the gauge inside the bearing sleeve to check that the diameter is not out of round.

Note: The gauge resolution should be 10% of the tolerance window. So, if tolerance is ± 0.0005 mm (± 0.00002 inch) the tolerance window is 0.001 mm (0.00004 inch) and the resolution must read at least 0.001 mm (0.00004 inch).

Checking Bearing Sleeve Surface Texture

Illustration 110	g03308640
Typical example of surface texture inspection.

After machining and inspecting the interior diameter of the gear bearing sleeve, it is critical to inspect the surface texture. Use 448-3698 Profilometer is recommended for measuring the surface texture. Refer to Section "Specifications" for the finish specifications.

Note: Before measuring the surface texture of the bearing sleeve, make sure that the bearing sleeve is clean and free of debris that could make the reading inaccurate.