Transmission Clutch Plates and Disc Assemblies with Rayflex Friction Material {3030, 3155, 3190} Caterpillar

Articulated Truck

735 (S/N: B1N1-UP)

735B (S/N: L4D1-UP; T4P1-UP)

735C (S/N: LFJ1-UP; TFJ1-UP)

740 (S/N: AXM1-UP; B1P1-UP)

740 EJECTOR (S/N: B1R1-UP; AZZ1-UP)

740B (S/N: L4E1-UP; T4R1-UP)

740B EJECTOR (S/N: L4F1-UP; T4S1-UP)

745C (S/N: LFK1-UP; TFK1-UP)

D35-HP (S/N: 3FD1-UP)

D350E (S/N: 9LR1-UP)

D350E Series II (S/N: 2XW1-UP)

D400 (S/N: 1MD1-UP)

D400D (S/N: 8TF1-UP)

D400E (S/N: 2YR1-UP)

D400E Series II (S/N: APF1-UP; 8PS1-UP)

D40D (S/N: 2JJ1-UP)

D44B (S/N: 8SD1-UP)

D550B (S/N: 5ND1-UP)

Backhoe Loader

420E (S/N: PRA1-UP; PHC1-UP; GAN1-UP; HLS1-UP; KMW1-UP)

430E (S/N: SCD1-UP; RLN1-UP; DDT1-UP; EAT1-UP)

432E (S/N: JBA1-UP; BXE1-UP; RXS1-UP)

442E (S/N: PCR1-UP; GKZ1-UP)

450E (S/N: EBL1-UP)

Integrated Toolcarrier

IT28G (S/N: WAC1-UP; EWF1-UP)

IT62H (S/N: M5G1-UP)

Landfill Compactor

826C (S/N: 87X1-UP)

826G (S/N: 7LN1-UP)

826G Series II (S/N: AYH1-UP)

826H (S/N: AWF1-UP)

836 (S/N: 3RL1-UP; 7FR1-UP)

836G (S/N: BRL1-UP; 7MZ1-UP)

836H (S/N: BXD1-UP)

Load Haul Dump

R2900 (S/N: BAR1-UP; 5TW1-UP)

R2900G (S/N: GLK1-UP; JLK1-UP)

Motor Grader

140H (S/N: 2ZK1-UP)

24H (S/N: 7KK1-UP)

24M (S/N: B9K1-UP)

Off-Highway Truck/Tractor

69D (S/N: 9SS1-UP; 9XS1-UP)

768C (S/N: 02X1-UP)

769C (S/N: 01X1-UP)

769D (S/N: BBB1-UP; 5TR1-UP; 5SS1-UP)

770 (S/N: BZZ1-UP)

772 (S/N: RLB1-UP; 10S1-UP)

772B (S/N: 64W1-UP)

773B (S/N: 63W1-UP)

773D (S/N: NBJ1-UP; 7ER1-UP; 7CS1-UP)

773E (S/N: BDA1-UP; ASK1-UP)

773F (S/N: EED1-UP; EXD1-UP)

776B (S/N: 6JC1-UP)

776C (S/N: 2TK1-UP)

776D (S/N: 5ER1-UP; AFS1-UP)

777B (S/N: 4YC1-UP)

777C (S/N: 4XJ1-UP)

777D (S/N: AGC1-UP; FKR1-UP; 3PR1-UP; 2YW1-UP; AGY1-UP)

777E (S/N: KDP1-UP)

777F (S/N: JRP1-UP; JXP1-UP)

777G (S/N: T5A1-UP; TNM1-UP; RDR1-UP; T4Y1-UP)

784B (S/N: 5RK1-UP)

784C (S/N: 2PZ1-UP)

785 (S/N: 8GB1-UP)

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

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

785D (S/N: DMC1-UP; MSY1-UP)

789 (S/N: 9ZC1-UP)

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

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

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

793 (S/N: 3SJ1-UP)

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

793C (S/N: CBR1-UP; 4AR1-UP; ATY1-UP; 4GZ1-UP)

793D (S/N: FDB1-UP)

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

On-Highway Transmission

All

Petroleum Power Train Package

TH48-E70-C32P (S/N: PKG1-UP)

Petroleum Transmission

All

Pipelayer

561H (S/N: 6NL1-UP)

561M (S/N: 1KW1-UP)

561N (S/N: TAD1-UP; CPH1-UP)

589 (S/N: 31Z1-UP)

Quarry Truck

771C (S/N: 3BJ1-UP)

771D (S/N: BCA1-UP; 6JR1-UP; 6YS1-UP)

773G (S/N: MWH1-UP; JWS1-UP)

775B (S/N: 7XJ1-UP)

775D (S/N: 6KR1-UP; 8AS1-UP)

775E (S/N: BEC1-UP)

775F (S/N: EYG1-UP; DLS1-UP)

775G (S/N: RFM1-UP; MJS1-UP)

Road Reclaimer/Soil Stabilizer

RM-350 (S/N: 5FK1-UP)

RM-350B (S/N: AXW1-UP)

RM-500 (S/N: ASW1-UP)

RM350B (S/N: 7FS1-UP)

SM-350 (S/N: 1RM1-UP)

Soil Compactor

825C (S/N: 86X1-UP)

825G (S/N: 6RN1-UP)

825G Series II (S/N: AXB1-UP)

825H (S/N: AZW1-UP)

Track-Type Loader

933 (S/N: 8FL1-UP; 9EL1-UP)

933C (S/N: 4MS1-UP; 5JS1-UP)

Track-Type Skidder

D4 TSKH Series III (S/N: 7PK1-UP)

Track-Type Tractor

D10 (S/N: 84W1-UP; 76X1-UP)

D10N (S/N: 2YD1-UP; 3SK1-UP)

D10R (S/N: 3KR1-UP; AKT1-UP)

D10T (S/N: RJG1-UP)

D11N (S/N: 4HK1-UP; 74Z1-UP)

D11R (S/N: AAF1-UP; 8ZR1-UP; 9TR1-UP; 9XR1-UP; 7PZ1-UP)

D11T (S/N: AMA1-UP; GEB1-UP; TPB1-UP; MDG1-UP; JEL1-UP; JNS1-UP)

D3C Series III (S/N: 6SL1-UP; 7XL1-UP; 9TS1-UP)

D4C Series III (S/N: 6YL1-UP; 7SL1-UP; 8CS1-UP)

D4H Series III (S/N: 8PJ1-UP; 9GJ1-UP)

D5C Series III (S/N: 9DL1-UP)

D5M (S/N: 6GN1-UP; 3CR1-UP; 3DR1-UP; 4BR1-UP; 7LR1-UP; 4JS1-UP; 5ES1-UP; 5FS1-UP; 6AS1-UP)

D5N (S/N: AKD1-UP; AGG1-UP; CFH1-UP; CKT1-UP)

D6D (S/N: 5YB1-UP; 6HC1-UP; 36C1-UP; 37C1-UP; 38C1-UP; 7YK1-UP; 9FK1-UP; 74W1-UP; 75W1-UP; 31X1-UP; 32X1-UP; 33X1-UP)

D8L (S/N: 4FB1-UP; 7YB1-UP; 7JC1-UP; 53Y1-UP)

D9N (S/N: 1JD1-UP; 6XJ1-UP)

D9R (S/N: 8BL1-UP)

D9T (S/N: RJS1-UP)

Underground Articulated Truck

AD30 (S/N: CXR1-UP; DXR1-UP)

AD40 Series II (S/N: 1YZ1-UP)

AD45 (S/N: BKZ1-UP)

AD45B (S/N: CXM1-UP)

AD55 (S/N: ANW1-UP; DNW1-UP)

AE40 Series II (S/N: BLW1-UP; 1ZZ1-UP)

Wheel Dozer

814S (S/N: 56D1-UP; 23K1-UP)

824C (S/N: 85X1-UP)

824G (S/N: 4SN1-UP)

824G Series II (S/N: AWW1-UP)

824H (S/N: ASX1-UP)

824S (S/N: 35G1-UP)

834B (S/N: 7BR1-UP; 92Z1-UP)

834G (S/N: BPC1-UP; 6GZ1-UP)

834H (S/N: BTX1-UP)

834S (S/N: 36G1-UP; 96G1-UP)

834U (S/N: 14B1-UP)

844 (S/N: BBN1-UP; 2KZ1-UP)

844H (S/N: BTW1-UP)

854G (S/N: AMP1-UP; A4W1-UP; 1JW1-UP)

854K (S/N: 2211-UP)

Wheel Loader

980C (S/N: 2EB1-UP; 13B1-UP; 2XD1-UP; 63X1-UP)

980F (S/N: 8CJ1-UP; 3HK1-UP)

980F Series II (S/N: 5XJ1-UP; 4RN1-UP; 8JN1-UP)

980G (S/N: 9CM1-UP; 2KR1-UP; 2SR1-UP)

980G Series II (S/N: AXG1-UP; AWH1-UP; AYT1-UP)

980H (S/N: MHG1-UP; A8J1-UP; KZL1-UP; JMS1-UP)

980K (S/N: W7K1-UP; GTZ1-UP)

988B (S/N: 50W1-UP)

988F (S/N: 8YG1-UP)

988F Series II (S/N: 2ZR1-UP)

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

988H (S/N: BXY1-UP)

990 (S/N: 7HK1-UP)

990 Series II (S/N: BCR1-UP; 4FR1-UP)

990H (S/N: BWX1-UP)

992C (S/N: 42X1-UP; 49Z1-UP)

992D (S/N: 7MJ1-UP)

992G (S/N: 7HR1-UP; AZX1-UP; ADZ1-UP)

992K (S/N: H4C1-UP)

993K (S/N: LWA1-UP; Z9K1-UP)

994 (S/N: 9YF1-UP)

994D (S/N: 3TZ1-UP)

994F (S/N: 4421-UP)

994G (S/N: 8FR1-UP)

994H (S/N: DWC1-UP)

Wheel Tractor-Scraper

613G (S/N: ESB1-UP)

621E (S/N: 6AB1-UP; 6BB1-UP; 2PD1-UP; 2TF1-UP)

621F (S/N: 4SK1-UP; 5JK1-UP; 8PL1-UP; 9NL1-UP)

621G (S/N: DBB1-UP; ANG1-UP; CEN1-UP; ALP1-UP; CEP1-UP; DBX1-UP)

621H (S/N: DBK1-UP; NYY1-UP; EAZ1-UP)

621R (S/N: 12Y1-UP)

621S (S/N: 8KD1-UP)

623E (S/N: 6CB1-UP; 6DB1-UP; 6YF1-UP; 5SG1-UP)

623F (S/N: 5SG1-UP; 6BK1-UP; 3XW1-UP; 5EW1-UP)

623G (S/N: AWB1-UP; DBC1-UP; CES1-UP; ARW1-UP; CEW1-UP; DBY1-UP)

623H (S/N: EJD1-UP; DBF1-UP)

627E (S/N: 6EB1-UP; 6FB1-UP; 6GB1-UP; 6HB1-UP; 7CG1-UP; 3WJ1-UP)

627F (S/N: 4YK1-UP; 1DL1-UP)

627G (S/N: DBD1-UP; AXF1-UP; AYK1-UP; CEX1-UP; CEZ1-UP; DBZ1-UP)

627H (S/N: LCT1-UP; DBW1-UP)

631B (S/N: 28F1-UP)

631C (S/N: 28F1-UP; 67M1-UP)

631D (S/N: 24W1-UP; 28W1-UP; 29W1-UP; 39W1-UP)

631E (S/N: 1AB1-UP; 1BB1-UP; 6PC1-UP; 4LD1-UP)

631E Series II (S/N: 1NB1-UP; 3ND1-UP)

631G (S/N: DFA1-UP; AWK1-UP; DEM1-UP; CLR1-UP; CMT1-UP; AXZ1-UP)

637E (S/N: 1FB1-UP; 1HB1-UP; 1JB1-UP; 1LB1-UP; 7CB1-UP)

637G (S/N: AWE1-UP; CEH1-UP; CEJ1-UP; DFJ1-UP; CEM1-UP; AYN1-UP; AXT1-UP; DEX1-UP; DEY1-UP)

637K (S/N: WTS1-UP; WTT1-UP; WTX1-UP)

651E (S/N: 5XR1-UP; 88Z1-UP; 89Z1-UP)

657E (S/N: 6MB1-UP; 6PR1-UP; 7KR1-UP; 86Z1-UP; 87Z1-UP; 90Z1-UP; 91Z1-UP)

657G (S/N: W1B1-UP; W1C1-UP; W1E1-UP; W1F1-UP; A4G1-UP; GER1-UP)

Introduction

Table 1

Revision	Summary of Changes in SEBF8098
21	Copyright date updated to 2018. Tables arranged in alpha numeric order. Updated Canceled Part Numbers and Replaced Part Numbers section. Tooling and Equipment table updated with tooling to perform Crack Detection Methods. Updated Crack Detection Methods.
20	Added serial numbers.
19	Updated effectivity.
18	Added 1 part number.

© 2018 Caterpillar All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law.

Information contained in this document is considered Caterpillar: Confidential Yellow.

This 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 the Numerical Part Record (NPR) on the Service Information System Website (SIS Web) for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Note: This document can be used for reuse and salvage procedures of the transmission clutch plates and disc assemblies with Rayflex friction material.

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 that it is safe for you and for other people to use. 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.

Show/hide table

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”. Refer to Illustration 2 for an example of a “WARNING” Safety Alert Symbol.

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 installation of new components is not often necessary during transmission repair. The installation of reconditioned components can result in large cost reductions. This document was developed to provide visual guidelines for reusing assemblies of clutch discs and clutch plates in transmissions. The clutch discs in the guideline are made with Rayflex material for friction on clutch discs.

During the reconditioning of a transmission with Rayflex discs, new friction discs should be installed if the discs are expected to last one life cycle. The life cycle of a transmission is dependent upon the application.

This publication provides guidelines for the following components for conducting a repair to a transmission that has experienced a failure that was not scheduled:

• Friction discs

• Clutch plates

• Pistons

• End housings

Use the following guidelines if a failure occurs in the middle of a life cycle and the transmission will be repaired.

When friction material is damaged in service and found to be glazed, eroded, or worn, the probable cause will not be the friction disc. Friction discs are durable and tolerant. When friction disc material fails, the following problems are the most probable causes:

• Incorrect clutch engagement

• Incorrect release of the clutch

• Insufficient pressure

• Incorrect lubrication

The control valves need to be closely inspected for damage and wear in these cases.

Never install a part that should not be used again according to this document. Even after many hours of use, the Rayflex friction material on clutch discs will normally be in good condition. The discs can be used again without reconditioning if none of the following damage exists:

• Scratches

• Smearing

• Discoloration

• Warp

• Dish

Procedures to recondition scratched surfaces, smeared surfaces, or lightly pitted faces of reaction are given in this guideline. Also, specifications for the maximum amount of warp and dish are given. Do not use any other method of cleaning or reconditioning including the following methods:

• Machining with a lathe

• Clean with grit or glass beads

• Clean with abrasive pads for reconditioning

Any method that changes the surface finish of the reaction surfaces can cause rapid wear of the friction material.

During reconditioning, correct any conditions that contributed to the original failure.

Note: Check the oil in the transmission to make sure that the oil is correct. Additives that are in some oils attack the friction material. Additives can result in a greatly reduced operating life.

Note: Although transmission discs that are made with Rayflex friction material are similar in appearance to discs that are made with F37 material, criteria for reusability are different. This guideline displays information on the reusability of Rayflex friction material.

References

Table 2

References
Media Number	Publication Type & Title
SEBF8014	Reuse and Salvage Guidelines , "Identification and Applications of Transmission Clutch Plates and Specifications to Machine Reaction Faces for Power Shift Transmissions"
SEBF8017	Reuse and Salvage Guidelines , "Clutch Ring Gears For All Power Shift Transmissions"
SEBF8178	Reuse and Salvage Guidelines , "Procedure to Salvage Tang Slots on Transmission and Brake Pistons"
SEBF8187	Reuse and Salvage Guidelines , "Standardized Parts Marking Procedures"

Service Letters and Technical Information Bulletins

Show/hide table

NOTICE
Refer to the most recent Service Letters and Technical Information Bulletins. 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.

Tooling and Equipment

Table 3

Required Tooling and Equipment
Part Number	Description	Designation
6V-2010	Polishing Stone	Clutch Plate Cleaning
Woodhill Chemical Sales Corporation	Naval Jelly	Clutch Plate Cleaning
9U-7377 (1)	Metal Marking Pen	Parts Marking
8T-7571	Cleaner	Friction Material Cleaning
486-1524	Cleaner	Friction Material Cleaning
486-1526	Degreaser	Friction Material Cleaning
448-3698	Indicator (Profilometer)	Surface Texture Tester
8S-2257	Magnifying Glass	Visual Surface Inspection (VT)
9U-6182	Mirror (Telescoping)	Visual Surface Inspection (VT)
9U-7231	Flashing Lights Conversion Kit	Visual Surface Inspection (VT)
4C-9442	Light	Visual Surface Inspection (VT)
— (2)	Bright Incandescent Light	Visual Surface Inspection (VT)
262-8390	Microscope (40-Power) Pocket	Crack/ Measurement Inspection
288-4209	Paper Towel	Liquid Penetrant Testing (PT)
1U-9915	Brush Curved Handle Wire	General Cleaning/ Liquid Penetrant Testing (PT)
—	Developer	Liquid Penetrant Testing (PT)
—	Penetrating Oil	Liquid Penetrant Testing (PT)
—	Solvent Cleaner	General Cleaning/ Liquid Penetrant Testing (PT)
263-7184	Crack Detection Kit (Magnetic Particle)	Dry Magnetic Particle Testing (MPT)
—	Paint Pen	Dry Magnetic Particle Testing (MPT)
459-0184	Lamp Group Ultraviolet	Wet Magnetic Particle Testing (MPT)

(1)	Available in the United States only.
(2)	Refer to Special Instruction , PERJ1017 , "Dealer Service Tools Catalog" for suitable tooling.

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.

Show/hide table

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.

Glossary

Chipped - Areas of friction material are broken off the disc assemblies.

Circumferential - Circular in shape

Discoloration - Change in color

Dished - Bent in the radial direction

Erosion - The condition that includes deterioration or breakage of the friction material on the land edges of friction discs

Glazed - The condition that includes the development of a smooth layer on the friction material that is similar in appearance to glass

Gouged - The condition that includes the removal of friction material by another object that results in grooves or cavities

Mating - Parts that operate together through contact

Nick - Small notch

Rubbing - Relative movement of two parts that are in contact

Smeared - The condition that includes the removal of material from one surface to another surface

Warp - Twisted out of shape

Disc Assembly

Identification

This document should only be used for the intended specific components. Caterpillar uses several different types of friction material on clutch plates. As a rule, assume that each type of friction material requires a different surface finish for the reaction face. Each type of friction material has different wear characteristics and failure modes.

The following section identifies the features of clutch discs with Rayflex friction material.

Note: Illustration 6 shows the only type of pattern used with Rayflex friction material.

Illustration 6	g01484493
This is a spiral pattern. Some discs have an X pattern of grooves on both sides. Rayflex material is dark gray or black. The surfaces and outside diameter are fully machined.

Cleaning Friction Material

Chlorinated solvents, diesel fuel, kerosene, and petroleum distillates can be used to clean discs with Rayflex friction material. Petroleum distillates include Stoddard Solvent and naphtha.

Rayflex material is porous. The material can be damaged by using incorrect materials for cleaning or incorrect processes. Incorrect materials and incorrect processes can weaken the friction material. Friction material that is weakened can lead to early failure.

Follow the following precautions:

1. Do not use solvents that have a higher temperature than 38 °C (100 °F).

2. Minimize the time of contact between solvents and discs.

3. Use towels or compressed air to dry the discs after washing.

4. To avoid chipping of friction material, do not stack discs. Clutch discs should be hung on hooks during storage.

Do not use any of the following types of cleaning materials. Do not permit the following materials for cleaning to come in contact with the Rayflex friction material. These materials will weaken the base material. These materials will cause the base material to break up in operation.

• Water or steam

• Water-based cleaning solutions such as 486-1526 Degreaser, 8T-7571 Cleaner, or 486-1524 Cleaner.

• Freon

• Thinner for paint

• Ketones, aldehydes such as MEK and acetone

Use a unit for washing that will allow the discs to be placed upright and separate. An example of a suitable unit for washing is shown in Illustration 7, Illustration 8, and Illustration 9. After washing, carefully hang the discs in a vertical position for temporary storage. Do not stack the discs.

Illustration 7	g01276412
The illustration shows a washer for discs.

Illustration 8	g01484753
The illustration shows a washer for discs.

Illustration 9	g01484853
The illustration shows a washer for discs.

Inspection of Piston, Clutch Plate, and Surfaces of Reaction

Specifications for Reconditioning Surfaces of Reaction

Illustration 10	g01485053
The illustration shows the detail of piston and/or center plate damage. Refer to Illustration 11 for Cross Section (B). (A) Area of wear (B) Cross Section

Illustration 11	g01614253
Cross Section (B) from Illustration 10 shows piston damage or damage from the center plate. (C) Pit (D) Bump of Material

Inspect the disc assemblies and plates to determine if the parts can be used again. Also, inspect the pistons and other reaction faces for the following damage to determine if the discs will need machining or salvaging procedures:

• Scratches

• Gouges

• Scuffing

• Wear

• Other damage

Some pistons and end faces that are used with nonmetallic friction material can develop small pits or tears on the face. The pits are in the shape of a tear. The pits are more distinct toward the outer diameter. The pits are visible with a magnifying glass. Refer to Illustration 10 and Illustration 11. Failure to replace the face and failure to resurface the face will cause rapid wear to the friction material. Use a circumferential grinder (100 grit) to resurface the disc. Grind the surface to an average surface texture of 0.38 µm (15 µin) to 0.88 µm (35 µin). Do not remove more than 0.13 mm (0.005 inch) of material from the piston or end face.

Handling Damage

Some damage to transmission discs may occur due to rough handling (contact with hard, sharp objects). Discs that meet the following guidelines may be reused. DO NOT REUSE discs that appear to be unusually soft or easily damaged.

Illustration 12	g01485134
The damaged area in this photo is approximately 20.0 mm2 (0.031 inch2).

Note: No more than six damaged areas are permitted per face. The maximum allowable area of handling damage on any face is 100.0 mm² (0.16 inch²).

Fatigue Damage

Do not reuse any discs that have suffered any chipping or obvious loss of friction material in the following forms:

• Chips

• Flaking

• Erosion

Note: Some chips at sharp points are acceptable if there are no other problems.

Illustration 13	g01485213
The illustration shows damage that is from fatigue.

DO NOT USE THIS PART AGAIN

Illustration 14	g01485214
The illustration shows an example of erosion that is from fatigue around the point on the diamond. Do not reuse the disc because the erosion is beginning on the edges of the diamonds. The arrows show erosion that is beginning on the edges.

DO NOT USE THIS PART AGAIN

Illustration 15	g01485233
The illustration shows the severe fatigue of the friction material. Do not reuse the disc because the material has suffered severe damage from fatigue on the edges of the lands.

DO NOT USE THIS PART AGAIN

Illustration 16	g01485414
The illustration shows severe erosion of the sides of the diamonds.

DO NOT USE THIS PART AGAIN

Bonding Failure

Illustration 17	g01485413
The illustration shows a clutch disc with bonding failure.

DO NOT USE THIS PART AGAIN

Glazing

Surfaces become glazed by the heat that is generated during excessive clutch slippage. The reduced coefficient of friction that results from the glazing causes more slippage and finally complete clutch failure. Glazing can be identified by a shiny appearance of the friction material.

Glazing can cover the entire surface. Glazing may be located just in bands. The normal surface has a porous appearance.

Note: No glazing is permitted.

Illustration 18	g01485415
The illustration shows a clutch disc with a glazed band. The top arrow shows the normal appearance that is dull. The lower arrow shows the smoother glazed band that is shiny.

DO NOT USE THIS PART AGAIN

Illustration 19	g01485417
The illustration shows a clutch disc with a glazed band. Each arrow points to a glazed band.

DO NOT USE THIS PART AGAIN

Illustration 20	g01485418
The illustration shows a clutch disc with glazed streaks.

DO NOT USE THIS PART AGAIN

Smearing

Illustration 21	g01485453
The illustration shows a clutch disc with smearing.

DO NOT USE THIS PART AGAIN

Cracked Teeth, Broken Teeth, or Worn Teeth

When the transmission is disassembled, carefully inspect each disc assembly. Any disc assembly that is broken, any disc assembly that is cracked, or any disc assembly that has deep grooves cannot be used again. Look for teeth that have been broken or have a crack. Inspect the reaction surface for radial cracks or deep grooves.

Reference: : Guidelines For Reusable Parts And Salvage Operations, SEBF8017, "Clutch Ring Gears For All Power Shift Transmissions"

Illustration 22	g01485454
Each arrow shows the location of a crack.

DO NOT USE THIS PART AGAIN

Tooth Wear

Disc assemblies should be inspected for tooth wear. Do not reuse a disc assembly if notches (wear steps) are worn into ALL the teeth.

Some wear is permitted. Some wear is especially permitted in clutches that have a load that is relatively light. Disc assemblies can be used again, if notches (wear steps) are worn into some of the teeth.

Illustration 23	g01485473
The illustration shows notches that are worn into the teeth of a clutch disc. (E) Normal tooth surface (F) Notch that is worn in the tooth

DO NOT USE THIS PART AGAIN

Illustration 24	g01485474
The illustration shows a clutch disc with shallow wear and no obvious step. (G) Shallow wear without an obvious step (H) Normal tooth surface

USE THIS PART AGAIN

Illustration 25	g01487615
Tooth wear is shown in the illustration.

DO NOT USE THIS PART AGAIN

Measurement of Face Wear and Disc Thickness

Excessively worn faces on discs can cause two types of problems:

• Insufficient stack height

• The restriction of the flow of oil for cooling because of the reduction of the oil groove depth.

Use a micrometer to measure the thickness at several places around the inner edges of the disc and the outer edges of the disc. DO NOT REUSE a disc that is below the minimum thickness that is shown in Table 4.

Note: Both sides of the disc should have the same amount of wear. Do Not Reuse a disc if the faces are not worn equal amounts.

Table 4

Wear Limits for Rayflex Friction Discs
Current Part Number	New Thickness	Minimum Thickness
3T-2466	5.59 ± 0.08 mm (0.220 ± 0.003 inch)	4.95 mm (0.195 inch)
3T-2467, 7T-2476	4.95 ± 0.10 mm (0.195 ± 0.004 inch)	4.49 mm (0.177 inch)
6I-8028	4.95 + 0.08 - 0.13 mm (0.195 + 0.003 - 0.005 inch)	4.37 mm (0.172 inch)
6I-8029	4.95 ± 0.08 mm (0.195 ± 0.003 inch)	4.37 mm (0.172 inch)
6I-9255	4.95 ± 0.10 mm (0.195 ± 0.004 inch)	4.54 mm (0.179 inch)
6T-1783	3.56 ± 0.08 mm (0.140 ± 0.003 inch)	2.95 mm (0.116 inch)
6T-2317	4.95 ± 0.10 mm (0.195 ± 0.004 inch)	4.34 mm (0.171 inch)
6T-2697, 9W-2473, 6Y-7220, 169-7055	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
6T-2698, 6Y-7218, 9W-7032	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
6T-4943	4.95 ± 0.08 mm (0.195 ± 0.003 inch)	4.39 mm (0.173 inch)
6Y-7219, 9W-7088	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
6Y-9807, 9W-7090, 158-3752	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
6Y-9808, 9U-9999, 9W-7089, 102-8671	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
7T-1860	5.59 ± 0.08 mm (0.220 ± 0.003 inch)	4.95 mm (0.195 inch)
8E-2477	5.59 ± 0.08 mm (0.220 ± 0.003 inch)	4.95 mm (0.195 inch)
9G-4400	5.59 ± 0.08 mm (0.220 ± 0.003 inch)	4.95 mm (0.195 inch)
9W-3006	5.59 ± 0.08 mm (0.220 ± 0.003 inch)	4.95 mm (0.195 inch)
106-3045	2.95 ± 0.1 mm (0.116 ± 0.004 inch)	2.70 mm (0.106 inch)
147-2280	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
147-4455	7.00 ± 0.08 mm (0.276 ± 0.003 inch)	6.10 mm (0.240 inch)
158-3750	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
221-9685	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
241-4890	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
262-7319	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
262-7320	5.56 ± 0.08 mm (0.219 ± 0.003 inch)	5.00 mm (0.197 inch)
313-5544	2.05 ± 0.08 mm (0.081 ± 0.003 inch)	1.77 mm (0.070 inch)
443-0663	6.38 ± 0.08 mm (0.251 ± 0.003 inch)	5.85 mm (0.230 inch)

Refer to Guidelines For Reusable Parts And Salvage Operations, SEBF8014, "Identification and Applications of Transmission Clutch Plates and Specifications to Machine Reaction Faces for Power Shift Transmissions" for additional information.

Clutch Plates

Nomenclature

Illustration 26	g01199158
The illustration shows the nomenclature for a transmission clutch plate. (A) Reaction Surface (B) Tang (C) Slot for Pin (D) Part Number (E) Inside Diameter (F) Outside Diameter

Cracked Clutch Plates or Broken Clutch Plates

Illustration 27	g01487757
The illustration shows a clutch plate with a broken tang.

DO NOT USE THIS PART AGAIN

Illustration 28	g01487760
The illustration shows a clutch plate with a radial crack.

DO NOT USE THIS PART AGAIN.

Wear on the Slot for the Pin

Illustration 29	g01622130
(G) Maximum Width of the Slot (H) Maximum Width of the Radial Indentation

Table 5

Wear Limits for the Slot for the Pin
Diameter of the Reaction Pin	Maximum Width of the Slot (G)	Maximum Width of the Radial Indentation (H)
12.70 mm (0.500 inch)	16.3 mm (0.64 inch)	9.7 mm (0.38 inch)
15.88 mm (0.625 inch)	19.3 mm (0.76 inch)	9.7 mm (0.38 inch)

Note: A plate that is worn may be reused under certain circumstances. The wear on the slot must only be on one side of the plate. The plate must meet all the limitations. The limitation on the radial indentation does not need to be met. The plate must be used in the same clutch and in the same application.

Refer to Guidelines For Reusable Parts And Salvage Operations, SEBF8178, "Procedure to Salvage Tang Slots on Transmission and Brake Pistons".

Note: Only use the procedures that are shown in "Scratched Clutch Plates" and "Smeared Faces of Reaction". Other methods can cause rapid wear of the disc assemblies.

Scratched Clutch Plates

Remove any sharp edges that have been caused by scratches or nicks by carefully rubbing only the area of the sharp edge with a 6V-2010 Polishing Stone or with 2/0 emery paper and a solvent. Rub the edge until the sharp edge cannot be felt with a fingernail or a lead pencil. Put oil on the plate or on the surface to prevent rust.

Illustration 30	g01487853
The illustration shows the use of a stone for polishing for the removal of a sharp edge that was caused by a scratch or a nick.

Measurement of Warped Areas and Dished Areas

1. Remove any rough edges in the area of the slot for the pin.

2. Put the clutch plate on a flat surface such as a clutch housing reaction surface, a center plate for a transmission, or a surface plate. If dishing is obvious, put the plate on the flat surface so the concave side is up.

3. Measure the gap between the clutch plate and the surface for inspection at Outside Diameter (L) and Inside Diameter (M). Measure the gap at a minimum of three points around the plate with equal distances between the points.

4. If Outside Gap (J) at the outside diameter at any of the points is more than 0.30 mm (0.012 inch) the clutch plate cannot be used again.

5. If Inside Gap (K) at the inside diameter at any of the points is more than 0.15 mm (0.006 inch), the clutch plate cannot be used again.

6. If the gaps that were measured in Step 4 and Step 5 are acceptable, subtract the measurement of Inside Gap (K) from the measurement of Outside Gap (J). If the difference is more than 0.15 mm (0.006 inch), the clutch plate cannot be used again.

Example

The measurement of Outside Gap (J) is 0.28 mm (0.011 inch), which is less than the maximum.

The measurement of Inside Gap (K) is 0.10 mm (0.004 inch), which is less than the maximum. This difference between the measurement of Outside Gap (J) and Inside Gap (K) is 0.18 mm (0.007 inch) which is more than the maximum. This example of a clutch plate cannot be reused.

The process of reconditioning the plate should not be continued if the plates are warped. The process of reconditioning the plate should not be continued if the plates are dished.

Illustration 31	g01487893
Measurements of Outside Gap (J) and Inside Gap (K).

Illustration 32	g01569485
Measurements of Outside Gap (J) and Inside Gap (K). (J) Outside Gap (K) Inside Gap (L) Outside Diameter (M) Inside Diameter

Smeared Faces of Reaction

Show/hide table

Personal injury can result from working with cleaning solvent. Because of the volatile nature of many cleaning solvents, extreme caution must be exercised when using them. If unsure about a particular cleaning fluid, refer to the manufacturer's instructions and directions. Always wear protective clothing and eye protection when working with cleaning solvents.

All the Rayflex Friction Material on a smeared clutch plate or on a surface must be removed by a solvent before the plate or the other surface is used again. Duro Naval Jelly will remove the friction material if the surface is not badly smeared. Other equivalent solvents will also remove the friction material if the surface is not badly smeared. Duro Naval Jelly is sold by Woodhill Chemical Sales Corporation. Woodhill Chemical Sales Corporation is a division of Loctite Corporation. For badly smeared surfaces, use methyl ethyl ketone. The solvent should be used at temperatures from 16 °C (60 °F) to 27 °C (80 °F). Remove the solvent and put oil on the surface.

Illustration 33	g01487933
The illustration shows a clutch plate that is being cleaned with solvent.

USE THIS PART AGAIN

Note: Avoid contact between the solvent and the friction material of a disc assembly. Use only the procedures that are shown in "Scratched Clutch Plates" and "Smeared Faces of Reaction". Any other method can cause rapid wear of the disc assemblies.

Circumferential Marks

Illustration 34	g01487935
The illustration shows a clutch plate that has circumferential marks that cannot be felt with a fingernail or a lead pencil. The arrow points to circumferential marks.

USE THIS PART AGAIN

Reuse this part after reconditioning. Recondition the part by using the 6V-2010 Stone for Polishing or 2/0 emery paper to remove the circumferential marks. The average for the tolerance of the surface texture is 0.38 µm (15 µin) to 0.88 µm (35 µin). Do not remove more than 0.13 mm (0.005 inch).

Discoloration

Illustration 35	g01487953
The illustration shows a clutch plate with discoloration on the inner diameter. Check for warping and dishing. Use the part again only if the warping and dishing are within specifications.

USE THIS PART AGAIN

Reuse this plate if the warped area and dished area are within the specifications.

Illustration 36	g01487954
The illustration shows a clutch plate with discoloration. Check for warping and dishing. Use the part again only if the warping and dishing are within specifications.

USE THIS PART AGAIN

Reuse this plate after reconditioning. The warped area and dished area must be within specifications. The average for the tolerance of the surface texture is 0.38 µm (15 µin) to 0.88 µm (35 µin). Do not remove more than 0.13 mm (0.005 inch).

Spots

Small areas of apparent overheating can form on the surfaces of plates. The quantity of spots and the color of spots can vary from one light brown spot to many dark spots.

• Plates with three or fewer brown spots may be reused after reconditioning.

• Do not reuse plates with spots without reconditioning.

• Do not reuse plates that exhibit blue or black spots.

Illustration 37	g01487955
The illustration shows blue and black spots on a clutch plate. The plate should not be reused because the plate exhibits blue and black spots.

DO NOT USE THIS PART AGAIN

Crack Detection Methods

Show/hide table

NOTICE
Regardless of which crack detection method is used, it is important that the instructions furnished with the detection equipment are followed closely when checking any component. Failure to do so may cause inaccurate results or may cause injury to the operator and/or surroundings.

There are four major crack detection methods or Non-Destructive Testing (NDT) listed in this section: Visual Surface Inspection (VT), Liquid Penetrant Testing (PT), and Dry / Wet Magnetic Particle Testing (MPT).

Crack detection methods or NDT is methods for testing components for cracks without damaging the component. VT, PT, and Dry/ Wet MPT are methods recommended. There may be more than one acceptable crack detection method for the testing of a given part, although PT is the most versatile. For example, the PT method can be used when testing smooth machined components such as shafts, gear teeth, and splines, but using the Wet MPT is more accurate. Refer to Table 6 for advantages and disadvantages and Table 7 for standards and requirements for these NDT methods.

Table 6

Crack Detection Methods Advantages vs. Disadvantages
Detection Method	Advantages	Disadvantages
Visual Surface Inspection (VT)	- Least Expensive - Detects most damaging defects. - Immediate Results - Minimum part preparation	- Limited to surface-only defects. - Requires inspectors to have broad knowledge of welding and fabrication in addition to Non-Destructive Testing (NDT).
Liquid Penetrant Testing (PT)	- Inexpensive - Minimal Training - Portable - Works on nonmagnetic material.	- Least Sensitive - Detects surface cracks only. - Rough or porous surfaces interfere with test
Dry Magnetic Particle (MPT)	- Portable - Fast/Immediate Results - Detects surface and subsurface discontinuities	- Works on magnetic material only. - Less sensitive than Wet Magnetic Particle Testing (MPT).
Wet Magnetic Particle (MPT)	- More sensitive than Liquid Penetrant Testing (PT). - Detects subsurface as much as 0.13 mm (0.005 inch).	- Requires power for light. - Works on magnetic material only. - Liquid composition and agitation must be monitored.

Table 7

Applicable Crack Detection Standards
Detection Method	Standard	Acceptance Criteria	Minimum Required Personnel Qualifications
Visual Surface Inspection (VT)	EN-ISO 5817 AWS D1.1	EN-ISO 5817 - Level B AWS D1.1 - Table 6.1	EN-ISO 9712 ANSI-ASNT SNT-TC-1A
Liquid Penetrant Testing (PT)	EN-ISO 3452 ASTM E165	EN-ISO 23277 AWS - D1.1	EN-ISO 9712 ANSI-ASNT SNT-TC-1A
Magnetic Particle Testing (MPT)	EN-ISO 17638 ASTM E709	EN-ISO 23278 - Level 1 AWS D1.1 - Table 6.1	EN-ISO 9712 ANSI-ASNT SNT-TC-1A

Visual Surface Inspection (VT)

Illustration 38	g06124166
Example of Visual Surface Inspection (VT) Tooling (A) Flashlight (or adequate light source) (B) Magnifying Glass (C) Tape Measure (or other measuring device) (D) Inspection Mirror

Refer to Tooling and Equipment Table 3 for part numbers.

Components that are to be tested using PT, or MPT shall first be subject to a Visual Surface Inspection (VT). VT is often the most cost-effective inspection method and requires little equipment as seen in Illustration 38. Personnel performing VT shall either be trained to a company standard or have sufficient experience and knowledge regarding the components being inspected. Personnel performing VT shall take routine eye exams.

Liquid Penetrant Testing (PT)

Show/hide table

Personal injury can result from improper handling of chemicals. Make sure you use all the necessary protective equipment required to do the job. Make sure that you read and understand all directions and hazards described on the labels and material safety data sheet of any chemical that is used. Observe all safety precautions recommended by the chemical manufacturer for handling, storage, and disposal of chemicals.

Materials and Equipment Required

Refer to Tooling and Equipment Table 3 for part numbers.

• Cleaner: Removes dirt before dye application and dissolves the penetrant making possible to wipe the surface clean.

• Penetration Oil: This solution is highly visible, and will seep into openings at the surface of a part with capillary action.

• Developer: Provides a blotting action, bringing the penetrant out of the discontinuities and providing a contrasting background to increase the visibility of the penetrating oil indications.

• Wire Brush: Removes dirt and paint.

• Cloth or Wipes: Use with cleaner and for other miscellaneous uses.

Liquid Penetrant Testing (PT)

Show/hide table

Personal injury can result from improper handling of chemicals. Make sure you use all the necessary protective equipment required to do the job. Make sure that you read and understand all directions and hazards described on the labels and material safety data sheet of any chemical that is used. Observe all safety precautions recommended by the chemical manufacturer for handling, storage, and disposal of chemicals.

Materials and Equipment Required

Refer to Tooling and Equipment Table 3 for part numbers.

• Cleaner: Removes dirt before dye application and dissolves the penetrant making possible to wipe the surface clean.

• Penetrating Oil: This solution is highly visible, and will seep into openings at the surface of a part with capillary action.

• Developer: Provides a blotting action, bringing the penetrant out of the discontinuities and providing a contrasting background to increase the visibility of the penetrating oil indications.

• Wire Brush: Removes dirt and paint.

• Cloth or Wipes: Use with cleaner and for other miscellaneous uses.

Procedure

Show/hide table

Illustration 39	g06103795
Typical example of pre-cleaning the testing area.

1. Preclean the area to be tested. Spray on cleaner/ remover to loosen any scale, dirt, or any oil. Wipe the area to be tested with a solvent dampened cloth to remove remaining dirt and allow the area to dry. Remove paint where there are visible cracks using paint remover or a wire brush.
   Show/hide table

   Illustration 40	g06103803
   Typical example of applying penetrating oil to areas to be tested.

2. Apply penetrant by spraying to the entire area to be tested. Allow 10 to 15 minutes for penetrant to soak. After the penetrating oil has been allowed to soak, remove the excess penetrating oil with clean, dry wipe.
   Show/hide table

   Illustration 41	g06103816
   Typical example of removing penetrating oil with a cloth.

3. The last traces of penetrating oil should be removed with the cleaner solvent dampened cloth or wipe. Allow the area to dry thoroughly.
   Show/hide table

   Illustration 42	g06103820
   Typical example of applying the developer.

4. Before using developer, ensure that the developer is mixed thoroughly by shaking the container. Hold the container approximately 203 - 305 mm (8.0 - 12.0 inch) away from the testing area. Apply an even, thin layer of developer over the testing area. A few thin layers are a better application method than one thick layer.
   Show/hide table

   Illustration 43	g06084042
   Typical example of cracks found during Liquid Penetrant Testing (PT).

5. Allow the developer to dry completely for 10–15 minutes before inspecting for cracks. Defects will show as red lines in white developer background, refer to Illustration 43. Clean the area of application of the developer with solvent cleaner.

Dry Magnetic Particle Testing (MPT)

Materials and Equipment Required

Refer to Tooling and Equipment Table 3 for part numbers.

Illustration 44	g06085930
(A) Indications shown by Dry Magnetic Particle Testing (MPT). (B) Electromagnetic Yoke (C) Dry Powder Bulb

1. Dry magnetic powder shall be of high permeability and low retentively and of suitable sizes and shapes to produce magnetic particle indications. The powder shall be of a color that will provide adequate contrast with the background of the surface being inspected.

2. Dry magnetic particles shall be stored in suitable containers to resist contamination such as moisture, grease, oil, non-magnetic particles such as sand, and excessive heat. Contaminants will manifest in the form of particle color change and particle agglomeration. The degree of contamination will determine further use of the powder.

3. Dry magnetic powder shall be tested in accordance with ASTM E709 Section 18 (Evaluation of System Performance/Sensitivity) when not performing.

4. Equipment should include a "U" shaped electromagnetic yoke made from highly permeable magnetic material, which has a coil wound around the yoke. This coil carries a magnetizing current to impose a localized longitudinal magnetic field into the part. The magnetizing force of the yoke is related to the electromagnetic strength and can be tested by determining the lifting power of a steel plate. The yoke shall have a lifting force of at least 4.5 kg (10 lbs).

5. Check dry powder blower routinely to ensure that the spray is a light, uniform, dust-like coating of the dry magnetic particles. Blower should also have sufficient force to remove excess particles without disturbing those particles that are evidence of indications.

6. All equipment shall be inspected at a minimum of once a year or when accuracy is questionable.

Procedure

1. Ensure surface to be inspected is dry and free from oil, grease, sand, loose rust, mil scale, paint, and other contaminants.

2. Apply the magnetic field using the yoke against the faces and inside diameter of each bore.

3. Simultaneously apply the dry powder using the dry powder blower.

4. Remove excess powder by lightly blowing away the dry particles.

5. Continue around the entire circumference of each bore. Position the yoke twice in each area at 1.57 rad (90°) to ensure that multiple directions of the magnetic field are created.

6. Observe particles and note if any clusters of particles appear revealing an indication.

7. Record the size and shape of any discontinuities or indications found.

Wet Magnetic Particle Testing (MPT)

Materials and Equipment

Refer to Tooling and Equipment Table 3 for part numbers.

Illustration 45	g06085937
(A) Indications shown by Wet Magnetic Particle Testing (MPT). (B) Electromagnetic Yoke (D) Ultraviolet Lamp

Illustration 46	g06003178
Pear Shaped Centrifuge Tube

1. Wet magnetic particles are fluorescent and are suspended in a vehicle in a given concentration that will allow application to the test surface by spraying.

2. Concentration:

   1. The concentration of the suspended magnetic particles shall be as specified by the manufacturer and be checked by settling volume measurements.

   2. Concentrations are determined by measuring the settling volume by using an ASTM pear shaped centrifuge tube with a 1 mL (0.034 oz) stem with 0.05 mL (0.0017 oz) divisions, refer to Illustration 46. Before sampling, the suspension shall be thoroughly mixed to assure suspension of all particles, which could have settled. A 100 mL (3.40 oz) sample of the suspension shall be taken and allowed to settle for 30 minutes. The settling volume should be between 0.1 mL (0.0034 oz) and 0.25 mL (0.0085 oz) in a 100 mL (3.40 oz) sample.

   3. Wet magnetic particles may be suspended in a low viscosity oil or conditioned water.

   4. The oil shall have the following characteristics:

      • Low viscosity not to exceed 5 mm²/_s (5 cSt) at any temperature at which the vehicle is to be used.

      • Low inherent fluorescence and be non-reactive.

   5. The conditioning agents used in the conditioned water shall have the following characteristics:

      • Impart good wetting characteristics and good dispersion.

      • Minimize foaming and be non-corrosive.

      • Low viscosity shall not exceed a maximum viscosity of 5 mm²/_s (5 cSt) at 38° C (100° F).

      • Non-fluorescent, non-reactive, and odorless.

      • Alkalinity shall not exceed a pH of 10.5.

3. Equipment should include a "U" shaped electromagnetic yoke made from highly permeable magnetic material, which has a coil wound around the yoke. This coil carries a magnetizing current to impose a localized longitudinal magnetic field into the part. The magnetizing force of the yoke is related to the electromagnetic strength and can be tested by determining the lifting power of a steel plate. The yoke shall have a lifting force of at least 4.5 kg (10 lbs).

Procedure

1. Ensure surface to be inspected is dry and free from oil, grease, sand, loose rust, mil scale, paint, and any other contaminants.

2. Apply the magnetic field using the yoke against the surface in the area to be inspected.
   Show/hide table

   Illustration 47	g03536210

3. For case hardened and ground surfaces:

   • Due to the sensitivity required to locate the grinding cracks, inspection of case hardened and ground surfaces require that the yoke is applied so that the magnetic field is 1.57 rad (90°) to the expected direction of the indications. Also, due to the increased sensitivity resulting when the yoke is energized, the yoke is not moved until the evaluation is completed in the first direction. An AC yoke shall be used. See Illustration 47 for an example of yoke placement.

4. Visually inspect for indications of discontinuities using the proper illumination.

5. Record the size and shape of any discontinuities found.