Inspection and Reuse of Critical Fasteners Used in All Engines {7553, 7553} Caterpillar

Caterpillar Products

All Cat Engines

Introduction

© 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 Caterpillar 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.

Canceled Part Numbers and Replaced Part Numbers

This document may include canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

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, ensure the safety of yourself and others. 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

Engine reconditioning does not necessarily result in the installation of new bolts as part of the reconditioning procedure. Bolts can often be reused with the same performance as new ones until the next overhaul. This guideline covers cylinder head, main bearing, connecting rod, counterweight, and flywheel bolts.

Compare the bolts that are shown in this guideline and the bolts removed from the engine to be reconditioned. Sometimes, the bolt will not be reusable.

Never install a bolt this guideline shows cannot be used again. If a bolt has wear or damage that is not shown in this guideline, do not reuse the bolt again.

Service Letters and Technical Information Bulletins

References

Tooling and Equipment

Replacement Parts

Consult the applicable Parts Identification manual for your engine.

Measurement Requirements

Nomenclature

Regular Bolts

Illustration 3	g02114433
Bolt nomenclature (1) Head (2) Washer face (3) Under head fillet (4) Shank (5) Threads

Illustration 4	g02114453
Three highest stress areas on a bolt

Patch Lock Bolts

Patch lock bolts are identified by the nylon patch thread adhesive applied to one side of the bolt, as shown in Illustration 5. Patch lock bolts are desirable for use in some vibratory applications because of the locking (adhesive) compound. This compound absorbs the vibrations without breaking, maintains the applied torque of the bolt, and can be reused. It is recommended, after the third removal, to install a new nylon patch lock bolt.

Illustration 5	g02114473
Patch lock bolt

Adhesive Lock Bolts

The bolts that have a pre-applied thread adhesive with 360 degree coverage are not reusable. Refer Illustration 6. Reapplying the adhesive locking compound to the bolt is difficult to do accurately. However, the discarded bolts may be cleaned and reused in another application requiring a different locking compound.

Illustration 6	g02114474
Adhesive lock bolt (A) No adhesive present on 2 ± 1 threads (B) Adhesive should be on 6 ± 2 threads

Reduced-Diameter Shank Bolts

Bolts with a reduced diameter shrank are special bolts designed to stretch more than a standard bolt to provide increased clamping force to a bolted joint. Reduced-diameter shank bolts are identified by a smaller diameter length between the head and the threaded end of the bolt. The length has a diameter less than the outside diameter of the threads. The area of reduced diameter is straight length rather than a tapered length as with a bolt that has experienced “necking”.

Illustration 7	g02114493
Reduced-diameter-shank bolt (C) Length of smaller diameter shank

Inspection

Note: Bolts showing handling damage (dings, dents, nicks, scratches, and so on) within any area of the bolt must be replaced with new. This does not include where the head will engage with the socket.

Use the following steps to perform the inspection for the bolt.

1. The head (1)

   1. Inspect for corrosion and pitting. Corrosion and pitting is allowable as long as the pitting does not interfere with the socket or wrench.

   2. Check for any cracking, chipping, or rounding of the corners. If this type of damage is present, do not reuse the bolt.

2. The under head fillet (3)

   1. Inspect for smoothness. The presence of wear indicated by a shiny line that has not raised any material does not cause a stress riser. The shiny line does not make the bolt unusable. If there are signs of corrosion, cracks, nicks, pits, or gouges, do not reuse the bolt.

3. The bolt washer face (2)

   1. Inspect for corrosion, burrs, and any other conditions that would cause stress risers.

   2. Inspect for flatness, making sure the bolt washer face properly seats against the joint surface.

   3. Inspect for corrosion or burrs that would not allow the bolt washer face to seat properly. If either condition is found, do not reuse the bolt.

4. The shank (4)

   1. Inspect for straightness. If there are signs of bending, necking, wear, corrosion, pitting, or cracks on the shank, do not reuse the bolt.

5. The bolt threads (5)

   1. Inspect for necking, corrosion, cracking, deforming, stripping, or any other physical damage. If this type of damage is present, do not reuse the bolt.

6. Check the nylon patch on patch lock bolts. These bolts should only be used three times before replacement.

7. If the bolt is an adhesive lock bolt, replace with a new unused bolt.

Necking

Bolts may show signs of necking, which can be caused by severe overloading. Do not use a bolt showing signs of necking.

Illustration 8	g06381791
Overloaded and plastically deformed (necked) bolt

Do not use again

Fretting and Fretting Corrosion

Fretting and fretting corrosion indicate joint movement. Fretting indicators are polishing and denting of surfaces.

Illustration 9	g03430435
Fretting on a con-rod washer face

Do not use again

Fretting corrosion indicators are microwelding, metal transfer, and reddish oxide formation.

Illustration 10	g03430377
Fretting corrosion is present at the mid-shank of this bolt. Note the reddish oxide deposit.

Do not use again

Corrosion

Corrosion occurs on bolts when there is a chemical reaction that eats away at the bolt. Corrosion leads to pitting which can cause a fatigue fracture in the bolt. Corrosion will give the surface of the bolt a rough, porous texture.

Illustration 11	g02116133
Bolts with pitting and a rough, porous texture on the shank of the bolt.

Do not use again

Note: Pitting can cause bolts to crack.

Illustration 12	g03430389
This bolt has suffered a fracture due to corrosion near the head of the bolt. Carefully inspect all bolts for corrosion.

Bolt Cleaning Method

One way to damage a bolt at overhaul is to clean the bolt improperly. If a bolt needs more than wiping off, clean the bolt in a mild petroleum-based solvent. Make sure that the solvent has not been contaminated with water. If contaminated, the solvent and water mixture will pit the bolt. Also, never clean a bolt with a chlorinated solvent. The chlorine will attack the bolt surface and leave pits. A pitted bolt will fail at low hours. Nylon patch lock bolts can also be cleaned using the following method. Adhesive lock bolts can be cleaned, but should not be reused in an application requiring an adhesive lock bolt.

Kynetx HD cleaner can be used at concentrations from 1 to 30 percent and temperatures from room temperature up to 93 °C (200 °F). Most tanks and washers run at around 10 to 15 percent concentration and 88 °C (190 °F). The concentration percentage is determined by the amount of grease and other materials to be removed from the bolt. Constant agitation of the bolts while immersed in the tank is recommended.

Reusability for Critical Fasteners in C - Series Engines

3500 Family Engine Bolt Reuse and Assembly Lube Type

C175 Engine Fasteners

Note: Never reuse flywheel bolts.

C175 High-Pressure Fuel Rail Bolts

Illustration 13	g03694679
High-Pressure Fuel Rail Bolts are single use only. DO NOT REUSE (1). (1) HP Fuel Rail Bolts

Visual Inspection of C175 428-7386 Bolt

The 428-7386 Bolt As replaces the 290-2541 Bolt. The current connecting rod bolts have elastomer rings bonded to the shank of the bolts. The elastomer rings reduce bolt vibration and fatigue during engine operation.

The connecting rod bolt can be reused if rod is disassembled before overhaul if the bolt passes a visual inspection and elastomer measurement inspection.

Reference: Refer to Disassembly and Assembly, KENR6052, "Pistons, Liners, and Connecting Rods - Install" for instructions on installing the connecting rod bolts.

Reference: To provide addition clarification and details, a Caterpillar Channel 1 video has been created outlining the critical steps installing C175 Connecting Rod Bolts. Reviewing the video is recommended prior to starting the process.

Note: A CWS login is required to access Caterpillar Channel 1 Videos.

Reference: Reuse And Salvage Guidelines, SEBF8187, "Standardized Parts Marking Procedures"

Nomenclature

Illustration 14	g03374255
(1) Head (2) Shank (3) Elastomer (4) Threads

Cleaning

Prior to a visual inspection or the taking of measurements the C175 rod bolt must be cleaned of all Molylube. Most cleaning can be accomplished with a clean shop towel. A shop towel will remove Molylube from the elastomer peaks, and leave minimal residue in the valleys. This cleaning method is typically sufficient for visual inspection and the taking of reuse measurements.

If the use of a solvent is required, then soaking or prolonged use must be avoided. Only mineral spirits is an acceptable solvent to clean the C175 Rod Bolt. Ensure that all safety precautions are obeyed when using hazardous chemicals.

Do not use any other common shop solvents including the parts washer, aerosol brake cleaner, and carburetor cleaner.

Visual Inspection

Illustration 15	g03374281
Use Again (A) Elastomer flash at ends. (B) Scuffing or abrasion of outer rib. No rolling, skiving, or cutting observed.

Illustration 16	g03374301
Use Again (C) Skiving at top of rib. Peeled portion is fully attached on one side, and no tail is observed. Only one occurrence at 5 mm (0.197 inch) long maximum allowed for reuse. (D) Elastomer flash axially on both sides of bolt.

Illustration 17	g03374325
Use Again (E) Abrasion or skiving of elastomer from rolling of material. No loose material observed. (F) Skiving of material at outer diameter and rolling of material observed. No more than one occurrence 5 mm (0.197 inch) long maximum allowed for reuse.

Illustration 18	g03374336
Use Again (G) Skived or cut elastomer. Flap of material is remaining. No more than one occurrence 5 mm (0.197 inch) long maximum allowed for reuse.

Illustration 19	g03374502
Do Not Use Again (H) Tip of elastomer rib peeling and rolling into a valley.

Illustration 20	g03374519
Do Not Use Again (I) Rib detached from elastomer sleeve. Rolling of elastomer.

Illustration 21	g03374531
Do Not Use Again (J) Rib rolled into adjacent valley. (K) Rib torn.

Elastomer Measurement

Measurement of the elastomer sleeve diameter must be performed for reuse acceptability based on the permanent compression of the elastomer material.

To take the measurements, use a 455-8106 Gauge-Block to determine if the rod bolt has enough elastomer material for another life. The gauge block is machined to the minimum reuse specification of the elastomer material.

If the rod bolt slides into the gauge block, then the rod bolt is too small in diameter for reuse. It is not necessary for the rod bolt to slide to the bottom of the gauge block. If the maximum outer diameter of the elastomer material slides past the gauge block chamfer and into the gauge block groove, then the rod bolt should not be reused.

The use of the gauge block allows the outside diameter of the elastomer material to be checked accurately and efficiently. It is important to measure the diameter without any additional pressure on the elastomer material. Calipers and micrometers have proven to be inaccurate in measuring the elastomer material.

The rod bolt will need to be placed into the gauge-block and under its own weight inspected for reuse. The instructions for this test are as follows.

1. Clean the Gauge-Block with a lint free towel and solvent.
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   Illustration 22	g03728588

2. Apply a film of clean engine oil onto the chamfers of the Gauge-Block. This film of oil will reduce the friction between the elastomer material and the gauge block providing a more accurate inspection.
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   Illustration 23	g03730215

3. Place a Rod Bolt onto the Gauge-Block. Do not apply any additional downward pressure. Give a slight vertical rocking motion from the thread end to release any friction between the elastomer material and the gauge block.
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   Illustration 24	g03728715
   Side-by-side reuse comparison (1) C175 Rod Bolt (2) Elastomer material (Left) Reusable C175 Rod Bolt (Right) Non-Reusable C175 Rod Bolt

4. Refer to Illustration 24. If the elastomer material keeps the rod bolt elevated above the chamfers (left side), then the rod bolt can be reused. If at any time the rod bolt slides into the gauge block groove (right side), then the rod bolt cannot be reused.

5. Rotate the rod bolt approximately 1/8 of a rotation and repeat the rocking motion.

   Repeat Step 5 four more times until the bolt has been rotated 180° in the gauge block. This process will ensure that the bolt has been measured entirely around the circumference.

Standard process to mark Main Stud after each time it is tightened

C175 main studs can be torqued up to 10 times before replacement is necessary. Marking the stud each time it is torqued will ensure that the stud is not used past its intended service life. Mark the stud by stamping an X on the stud end every time the stud is torqued. Stamp away from the outside of the stud near the threads to prevent damage to the stud. 25 and 26.

Illustration 25	g06277746
Example of stud without markings

Illustration 26	g06277743
Example of stud after stud has been tightened. Marks can be made with an X stamp. Be sure to stay away from thread area when stamping.

3600 and C280 Engine Fasteners

Use the following guidelines to determine the serviceability of the fasteners:

Thoroughly inspect the fasteners before you reuse any fastener. Do not reuse a fastener that has any damage. Do not reuse a fastener that has any of these defects:

• Rust

• Nicks

• Thread damage

• Cracks

• Pits

• Deformation

If the fasteners appear to be free of defects, also follow these guidelines:

• Replace any stud for the cylinder head after the stud has been tensioned 20 times. This criteria includes the 1W-2363 Taperlock Stud, 7E-8400 Taperlock Stud, and 187-0450 Taperlock Stud.

• Also replace any stud for the main bearing cap ( 1W-0121 Taperlock Stud) after the stud has been tensioned 20 times.

• The cross tie bolt for the main bearing cap ( 3S-7079 Bolt) can only be tensioned five times.

• For the Torque Turn Bolts 1W-0098, 369-7181, and 467-0537, refer to Engine News, SEBD9992, "A New Torque Procedure for Connecting Rod Bolts Is Now Used on 3600, G3600, and C280 Engines".

1. Inspect connecting rod bolts at each service of the connecting rod bearings. There should be no fretting on the shank, knurled or annular ring area (2) of the connecting rod bolt. Ensure that the connecting rod bolt meets the guidelines for the reusable parts. Do not reuse the connecting rod nuts.

2. Prior to installation of the new 467-0537 Bolt As, inspect heat shrink tube (1). The tube serves as an alignment sleeve for the bolts.

   1. The heat shrink tube must be firmly in place and must not move under light finger pressure.

   2. The whole surface of the tube must be smooth.

   3. The tube must not extend into the fillet that is under the bolt head.

3. If a problem is found with the tube, use the following replacement procedure.

   1. Carefully cut the heat shrink tube from the bolt.

   2. Ensure that there is no damage to the shank of the bolt that was under the tube.

   3. Clean the shank of the bolt with solvent to remove any oil.

   4. Install a new 369-7183 Heat Shrink Tube onto the bolt. Position the tube approximately 1.5 mm (0.05906 inch) under the bolt head, away from the fillet that is under the bolt head.

   5. Use a heat gun or place the bolt and tube in an oven at 135° ± 14°C (243° ± 25°F) for 10 minutes. The tube must shrink into place without any bumps or wrinkles.

   6. After the bolt cools, the tube must be firmly in place. The tube must not move under light finger pressure.

   7. Make sure that the surface of the tube is smooth all around. Verify that the tube does not extend onto the fillet that is under the bolt head.

Note: The 467-0537 Bolt may be tightened for a maximum of five times. The reuse includes retightening after checking the rod bore or bearing clearance. Do not reuse the connecting rod nuts.

Illustration 27	g06381848
The old knurled bolt. (X) Dimension

Hydraulic Tension Bolt 463-9619

Illustration 28	g06101134
(3) Connecting Rod Bolt (10) 369-7183 Heat Shrink Tube (Y) 1.5 mm (0.05906 inch) spacing

1. Inspect connecting rod bolts at each service of the connecting rod bearings. There should be no fretting on the shank or annular ring area of the connecting rod bolt.

2. Prior to installation of the new Bolt As, inspect heat shrink tube (10). The tube serves as an alignment sleeve for the bolts.

   1. The heat shrink tube must be firmly in place and must not move under light finger pressure.

   2. The whole surface of the tube must be smooth.

   3. The tube must not extend into the fillet that is under the bolt head.

   4. If a problem is found with the tube, use the following replacement procedure:

3. Carefully cut the heat shrink tube from the bolt.

   1. Ensure that there is no damage to the shank of the bolt that was under the tube.

   2. Clean the shank of the bolt with solvent to remove any oil.

   3. Install a new 369-7183 Heat Shrink Tube onto the bolt. Position the tube (Y) approximately 1.5 mm (0.05906 inch) under the bolt head, away from the fillet that is under the bolt head.

   4. Use a heat gun or place the bolt and tube in an oven at 135° ± 14°C (243° ± 25°F) for 10 minutes. The tube must shrink into place without any bumps or wrinkles.

   5. After the bolt cools, the tube must be firmly in place. The tube must not move under light finger pressure.

   6. Make sure that the surface of the tube is smooth all around. Verify that the tube does not extend onto the fillet that is under the bolt head.

The connecting rod bolt (3) may be reused if it meets bolt reuse guidelines. An overloaded bolt can be detected by threading a new connecting rod nut onto the bolt by hand. If the threads are not damaged the new connecting rod nut will easily reach the end of the bolt thread with light finger pressure. If connecting rod nut stops before reaching the end, do not reuse the bolt.