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AAR Circular Letter C-8526 |
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AAR Circular Letter C-8526 |
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April 10, 1996
CIRCULAR LETTER
(c-8526)
Subject: Implementatation of Modification of Specification M-967 Section G II, Rules 1 and 2
TO MEMBERS AND PRIVATE CAR OWNERS
File Number: TWBL – 22.4
In Circular Letter c-8417, dated October 20, 1995, comments were solicited concerning a proposed modification of Section G II, Rules 1 and 2. Comments received were positive and the attached modifications were approved. The effective date is May 10, 1996 to allow shops time to modify their procedures to implement the modifications.
These provisions were added to cover plating of axle dust guards. This is your authority to update Section G II to include the attached modifications.
Sincerely,
Thomas J. Stahura
Director, Equipment Performance
MANUAL OF STANDARDS AND RECOMMENDED PRACTICES
SECTION G – PART II
Rule 2A5 to be renumbered to Rule 1C6 and the following paragraph added:
Rules 1A10 and 1C4 should have the reference to 2A5 changed to 1C6.
PRESENT
Rule 2A5 New or second hand roller bearing axle journals that are undersized or secondhand axle journals that are long or have a groove caused by the inboard seal wear ring may be repaired by an electrochemical metal deposition process providing they meet the following requirements
PROPOSED
Rule 1C6 All roller bearing axle journals and dust guards that are undersized or secondhand axle journals that are long or have a groove caused by the inboard seal wear ring may be repaired by an electrochemical metal deposition process providing they meet the following requirements.
PRESENT
Paragraph (f): Buildup of roller bearing axle journal by electrochemical metal deposition shall be performed only in facilities which have been certified according to the controlling Specification M-967, and only by operators certified according to Specification M-967.
PROPOSED
Paragraph (f): Buildup of roller bearing axle journal or dust guard by electrochemical metal deposit shall be performed only in facilities which have been certified according to the controlling Specification M-967, and only by operators certified according to Specification M-967.
PRESENT
Paragraph (g): Under no circumstances shall an axle journal be repaired by the electrochemical metal deposition process that shows signs of overheat or discoloration due to an overheated bearing. Any circumferential steps or grooves encompassing the entire surface of the axle journal in the bearing seat area greater than 0.001" deep is a sign of a loose cone and is considered an overheated axle. Axles which have severe water etch more than 50% of the area of a bearing seat may not be restored. Water etch less than 50% of the circumference may be restored.
PROPOSED
Paragraph (g): Under no circumstances shall an axle ------be repaired by the electrochemical metal deposition process that shows signs of overheat of discoloration due to an overheated bearing. Any circumferential steps or grooves encompassing the entire surface of the axle journal in the bearing seat area greater than 0.001" deep is a sign of a loose cone and is considered an overheated axle. Axles which have severe water etch more than 50% of the area of a bearing seat may not be restored. Water etch less than 50% of the circumference may be restored.
PRESENT
Figure 4.47 STATUS CODE EXPLANATION
1 – Wheel Mounting Shop…
2B – Approved Roller Bearing Repair Shop…
2F – Approved Roller Bearing Repair Shop…
2P – Approved Roller Bearing Repair Shop…
3 – M-967 Axle Repair Shop – Freight Car
4…
PROPOSED
Figure 4.47 STATUS CODE EXPLANATION
1 – Wheel Mounting Shop…
2B – Approved Roller Bearing Repair Shop…
2F – Approved Roller Bearing Repair Shop…
2P – Approved Roller Bearing Repair Shop…
3A – M-967 Axle Repair Shop – Journal, Seal Wear Ring
Groove and Water Etch repairs – Freight Cars
3B – M-967 Axle Repair Shop – Journal repairs only – Freight Car
3C – M-967 Axle Repair Shop – Dust Guard repairs only – Freight Car
4…
PRESENT
(title)
SPECIFICATION M-967-91
ELECTRO-CHEMICAL METAL DEPOSITION FOR
REPAIRING ROLLER BEARING AXLE JOURNALS
PROPOSED
(title)
SPECIFICATION M-967-91
ELECTRO-CHEMICAL METAL DEPOSITION FOR
REPAIRING ROLLER BEARING AXLE JOURNALS AND DUST GUARDS
PRESENT
1.0 SCOPE This document describes the certification requirements, equipment, materials, personnel requirements, quality control and utilization of the electrochemical metal deposition process for repairing roller bearing axle journals.
PROPOSED
1.0 SCOPE This document describes the certification requirements, equipment, materials, personnel requirements, quality control and utilization of the electrochemical metal deposition process for repairing roller bearing axles ---------.
PRESENT
3.0 APPLICATIONS The electro chemical metal deposition process can be used effectively on specific surfaces, as listed in Section – G Part II, Rule 2A5, where a metal deposit is required for restoration of original dimensions on roller bearing axle journals.
PROPOSED
3.0 APPLICATIONS The electrochemical metal deposition process can be used effectively on specific surfaces, as listed in Section – G, Part II, Rule 1C6, where metal deposit is required for restoration of original dimensions on roller bearing axle journals and dust guards.
PRESENT
Paragraph 5.1.2: The course shall provide the operator proficiency in the electrochemical metal deposition process including:
The demonstration of ability shall consist of properly repairing at least two journals with each of the following defects:
PROPOSED
Paragraph 5.1.2: The course shall provide the operator proficiency in the electrochemical metal deposition process including:
The demonstration of ability shall consist of properly repairing at least two journals with each of the following defects:
For Status Code 3A:
For Status Code 3B
For Status Code 3C
Proper repairing shall be determined by testing 100% of the repaired journals and dust guards in accordance with Section 5.2.1, 5.2.2, 5.2.3 and 5.2.4, except in the case of dust guard repairs where Section 5.2.3 does not apply.
PRESENT
5.2.4 Surface Finish The deposit finish on the repaired journal must not exceed 63 microinches.
PROPOSED
5.2.4 Surface Finish The deposit finish on the repaired journal must not exceed 63 microinches. The deposit finish on the repaired dust guard must not exceed 125 microinches.
PRESENT
Paragraph 5.2.5: Dimensional Inspection (Reference Figure 4.3)
When restoration of the entire length of the journal is required, journal diameters must be within the prescribed tolerances for new axles except for the restored area of the journal diameter outside the area bounded by the inboard edge of the seal wear ring to the outboard edge of the outboard cone, see Figure 1, dimension A. The radius of the journal fillet must meet new axle dimensions.
PROPOSED
Paragraph 5.2.5: Dimensional Inspection (Reference Section G – Part II, Figure 4.43)
When restoration of the entire length of the journal is required, average journal diameters must be within the prescribed tolerances for new axles except for the restored area of the journal diameter outside the area bounded by the inboard edge of the seal wear ring contact area, to the outboard edge of the outboard cone, see Figure 1, dimension A. The average journal diameter may be used to meet journal diameter requirements for Section G, Part II, Figure 4.3. The radius of the journal fillet must meet new axle dimensions. When restoring the dust guard for use in fitted applications, the diameter of the repaired dust guard must be within the prescribed tolerances for new axles.
PRESENT
Appendix A
Paragraph 3.0: All costs non-member applicants are to be paid upon notification of the testing charges. Product testing shall consist of the applicants furnishing a minimum of three axles with journals electrochemically repaired and shall include:
PROPOSED
Appendix A
Paragraph 3.0: All costs for non-member applicants are to be paid upon notification of the testing charges. Product testing shall consist of the applicants furnishing a minimum of three axles ----- electrochemically repaired and shall include (as required by the applicable status code number):
PRESENT
Appendix A
Paragraph 3.1.4 All journals must be measured and meet dimensional requirements as per Section 5.2.5.
PROPOSED
Appendix A
Paragraph 3.1.4 All journals and dust guards must be measured and meet dimensional requirements as per Section 5.2.5.
PRESENT
Appendix A
Paragraph 3.1.5 All journals must be measured and meet the surface finish requirements per Section 5.2.4.
PROPOSED
Appendix A
Paragraph 3.1.5 All journals and dust guards must be measured and meet the surface finish requirements per Section 5.2.4.
PRESENT
Appendix A
Paragraph 3.1.8 Blank
PROPOSED
Appendix A
Paragraph 3.1.8 3.1.8: Mounting and removal of a fitted backing ring three times on restored dust guards