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 GE Aviation authorizes the Federal Aviation Administration to incorporate this document by reference in an Airworthiness Directive.
Copyright (2015) General Electric Company, U.S.A.
TRANSMITTAL INFORMATION
REVISION 3 TO SERVICE BULLETIN 72-0114
Revision 3 is issued to update paragraphs 1., PLANNING INFORMATION, 2., MATERIAL INFORMATION, and 3.B., Rework.
Revision 2 was issued March 02, 2015. Revision 1 was issued January 14, 2013. The original was issued December 04, 2012. Revision bars in the left margin identify changes.
1.PLANNING INFORMATION
A.Effectivity
* * * FOR GEnx-1B64, -1B64/P1, -1B67, -1B67/P1, -1B70, -1B70/P1, -1B70/75/P1
This Service Bulletin is applicable to all GEnx-1B engines.
This Service Bulletin has been introduced in production to these GEnx-1B engines:
•
GEnx-1B engines, serial numbers 956-102, 956-103, 956-104, 956-105, 956-106, 956-109, 956-112, 956-113, 956-114, 956-124, 956-125, 956-157, 956-175, 956-192, and up.
These serial numbers are the best available data.
The mid fan shaft assembly P/N 2305M64G02, mid fan shaft P/N 2331M20G02, mid fan shaft assembly P/N 2305M64G03, mid fan shaft P/N 2332M81G01, and forward lock nut 2331M28P01 are affected by this Service Bulletin.
B.Description
This Service Bulletin releases a new mid fan shaft assembly P/N 2305M64G04, new mid fan shaft P/N 2331M20G03, new mid fan shaft assembly P/N 2305M64G05, new mid fan shaft P/N 2332M81G03, and a new forward lock nut P/N 2331M28P02.
C.Compliance
Category 4
GE recommends that you do this Service Bulletin when the forward lock nut is exposed.
NOTE:
This Service Bulletin can be accomplished in shop.
  NOTE:
Compliance with this Service Bulletin is terminating action for the current GEnx-1B S/B 72-0107 and prior versions for inspection of mid fan shaft.
This Service Bulletin is offered to improve the reliability or performance of your GE product, or to help prevent the occurrence of the event or condition described in this Service Bulletin. If the operator elects not to participate in the bulletin, that decision will be taken into consideration by GE in evaluating future product performance issues that may arise in the operators fleet.
D.Concurrent Requirements
The new fan mid shaft and forward lock nut must be used as a set. An intermix of part numbers is not permitted.
 
LIFE LIMIT
 
The life limit for the new mid fan shaft P/N 2331M20G03 and new mid fan shaft P/N 2332M81G03, have been added to the GEnx-1B Engine Manual (EM), Section 05-11-04. Refer to the GEnx-1B EM for cycle time limits of this parts.
E.Reason
(1)Objective:
To introduce new parts and improve reliability.
(2)Condition:
Fan mid shafts have been found cracked in the forward threaded area.
(3)Cause:
The combination of the current dry film lubricant (Everlube) and coupling nut assembly lubricant (graphite grease) have been determined to contribute to environmentally assisted cracking of the mid fan shaft.
(4)Improvement:
The new mid fan shaft uses a different dry film lubricant (Molydag). The new forward lock nut uses a different dry film lubricant (Molykote). The new mid fan shaft and forward lock nut use engine oil as an assembly lubricant. This combination of lubricants does not contribute to any cracks.
The mid fan shaft and coupling nut assembly torque has been adjusted to account for the change in assembly friction for this new lubricant combination.
(5)Substantiation:
Substantiation is by analysis and comparative analysis.
F.Approval
This Service Bulletin has been reviewed by the FAA and the repair(s) and modification(s) herein comply with the applicable Federal Aviation Regulations and are FAA APPROVED for installation in the model(s) listed in this Service Bulletin.
 Revision 3 of this Service Bulletin is approved by the Manager, Engine Certification Office, ANE-140, by letter dated December 21, 2015, as an Alternative Method of Compliance (AMOC) to Airworthiness Directive (AD) 2012-19-08, paragraphs (f)(1) and (f)(2).
G.Manpower
No additional man-hours are required to comply with this Service Bulletin.
H.Weight and Balance
Weight and balance are not changed.
I.References (Use the latest version of these documents)
 Airworthiness Directive (AD) 2012-19-08
GEK 112851, GEnx-1B Engine Manual (EM)
GEK 112862, GEnx-1B Cleaning, Inspection, and Repair Manual (CIR)
GEK 112864, GEnx-1B Engine Illustrated Parts Catalog (EIPC)
GEnx-1B S/B 72-0107, Inspection of Mid Fan Shaft
 Repair Document (RD) 810-272 (P1 or higher), Low Pressure Mid Shaft Assembly - Mid Fan Shaft - Alteration - Aluminum Coating and Dry Film Lubricant Replacement
  NOTE:
Deleted.
NOTE:
The reference documents listed below are for the engine manufacturer's internal use only:
 
CID: 573718
 
BPP: 12-72-56-01
J.Publications Affected
GEK 112864, GEnx-1B Engine Illustrated Parts Catalog (EIPC)
K.Interchangeability
Replace all hardware from the old part numbers to the new part numbers.
The old part numbers are not to be reinstalled.
L.Software Accomplishment Summary
Not applicable.
2.MATERIAL INFORMATION
A.Material - Price and Availability
(1)Parts necessary to do this Service Bulletin:
 
Part Number
Qty/ Eng
Part Name
Unit ($) Price
Pkg Qty
Lead Time Days
 
2305M64G04
(1)
Shaft, Mid Fan
371,654.00
(1)
Quote
 
2305M64G05
(1)
Shaft, Mid Fan
371,654.00
(1)
30
 
2331M28P02
(1)
Nut, Forward Lock
5,566.00
(1)
5
NOTE:
Prices are provided for planning purposes and are subject to change.
(2)Other Spare Parts:
None.
(3)Consumables:
 
Code Number
Description
 
C02-019
Oil, Engine Lubricating (engine oil)
 
C02-023
Oil, Engine Lubricating (engine oil)
 
C04-003
Solvent, General (acetone)
 
C05-003
Marking Pens
 
C10-182
Cloth, Cleaning for Aircraft Structural (SAE-AMS 3819, BMS 15-5) (cleaning cloth)
B.Industry Support Information
Contact your Customer Support Manager (CSM) for industry support information.
C.Configuration Chart
 
New Part Number
Qty/ Eng
Part Name
Old Part Number/ IPC Location
Qty/ Eng
Op Code
Chg/ Sprt Code
 
2376M20G02/G05
(1)
Propulsor Module Assembly
2330M20G02/G05
(1)
RM
-/-
 
.2305M64G04
45-010A, 72-00-02
(1)
Shaft, Mid Fan
(SIN 81000)
.2305M64G02
45-010, 72-00-02
(1)
RW/RE
5/A
 
..2331M20G03
01-010A, 72-58-00
(1)
Shaft, Mid Fan
(SIN 810A0)
..2331M20G02
01-010, 72-58-00
(1)
RW/RE
5/A
 
.2331M28P02
20-330A, 72-00-02
(1)
Nut, Forward Lock
(SIN 83006)
.2331M28P01
20-330, 72-00-02
(1)
RE
5/A
 
2376M20G06/G09
(1)
Propulsor Module Assembly
2330M20G06/G09
(1)
RM
-/-
 
.2305M64G05
45-011A, 72-00-02
(1)
Shaft, Mid Fan
(SIN 81000)
.2305M64G03
45-011, 72-00-02
(1)
RW/RE
5/A
 
..2332M81G03
01-011A, 72-58-00
(1)
Shaft, Mid Fan
(SIN 810A0)
..2332M81G01
01-011, 72-58-00
(1)
RW/RE
5/A
 
.2331M28P02
20-330A, 72-00-02
(1)
Nut, Forward Lock
(SIN 83006)
.2331M28P01
20-330, 72-00-02
(1)
RE
5/A
Operation Codes
RE=Replace
RM=Remains
RW=Rework
Change Code
5=Qualified interchangeability. Refer to paragraph 1.K., Interchangeability.
Support Code
A=Old parts will no longer be supplied.
D.Parts Disposition
 Retain the mid fan shaft for possible rework.
E.Tooling - Price and Availability
 
Tool Number
Description
 
11C3423G02
Fixture, Torque - LPT/Fan Coupling Nut (coupling nut torque fixture)
 
11C4272G01
Fixture, Extension - LPT Mid Shaft (extension fixture)
3.ACCOMPLISHMENT INSTRUCTIONS
A.Removal
(1)Remove the low pressure turbine (LPT) module assembly (45-020, 72-00-02). Refer to the GEnx-1B EM, 72-00-04, REMOVAL 001, and as follows:
(a)After the removal of the forward lock nut (2, Figure 1) in GEnx-1B EM, 72-00-04, REMOVAL 001, Subtask 72-00-04-020-041, clean the forward threads of the mid fan shaft as follows:
WARNING:
REFER TO THE PRODUCT LABEL AND THE MANUFACTURERS (MATERIAL) SAFETY DATA SHEET FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND PROPER USE OF THIS PRODUCT.
1Clean to remove the graphite grease from the threads of the mid fan shaft (1, Figure 1) with a C10-182 cleaning cloth moist with C02-019 engine oil or C02-023 engine oil.
WARNING:
REFER TO THE PRODUCT LABEL AND THE MANUFACTURERS (MATERIAL) SAFETY DATA SHEET FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND PROPER USE OF THIS PRODUCT.
2Continue to clean the threads of the mid fan shaft (1) with a C10-182 cleaning cloth moist with C04-003 acetone.
3Remove the low pressure turbine (LPT) module assembly (45-020, 72-00-02) with the mid fan shaft (1). Refer to the GEnx-1B EM, 72-00-04, REMOVAL 001.
4Remove the mid fan shaft (1) from the LPT module assembly (45-020, 72-00-02). Refer to the GEnx-1B EM, 72-00-04, DISASSEMBLY 001.
WARNING:
REFER TO THE PRODUCT LABEL AND THE MANUFACTURERS (MATERIAL) SAFETY DATA SHEET FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND PROPER USE OF THIS PRODUCT.
5Clean to remove the graphite grease from the surface and splines of the forward fan shaft (01-170- 72-24-00) with a C10-182 cleaning cloth moist with C02-019 engine oil or C02-023 engine oil.
WARNING:
REFER TO THE PRODUCT LABEL AND THE MANUFACTURERS (MATERIAL) SAFETY DATA SHEET FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND PROPER USE OF THIS PRODUCT.
6Continue to clean the surface and splines of the forward fan shaft (01-170) with a C10-182 cleaning cloth moist with C04-003 acetone.
(b)Conduct a close visual inspection to verify that the cleaning has removed all the graphite grease to prevent contamination.
B.Rework
NOTE:
If a new mid fan shaft is to be installed, continue with paragraph 3.C. Installation.
NOTE:
The mid fan shaft must be replaced with the new configuration or have the repair performed to update it to the new configuration. The mid fan shaft with the old configuration must not be installed.
 
NOTICE
 
APPROVAL OF REWORK SOURCES
 
The repair referred to below contains complex processes that could affect engine reliability and/or performance. Therefore it is necessary to substantiate the ability and adequacy of a repair source to successfully accomplish the repair. A Technical License Agreement is also required. Information concerning a Technical License Agreement is available from:
 
ATTN.: Manager, Technical Licensing
GE Aviation
One Neumann Way, M/D RM100
Cincinnati, Ohio 45215-6301
U.S.A.
 
After the repair source has obtained a Technical License Agreement, the Repair Document and the Repair Source Substantiation requirements may be obtained from:
 
ATTN.: Repair Substantiation
GE Aviation
One Neumann Way, M/D S171
Cincinnati, Ohio 45215-6301
U.S.A.
OR
Phone: (513) 552-9563
Fax: (513) 552-9587
 (1)The mid fan shaft (1, Figure 1) can be reworked to the new mid fan shaft. Refer to RD 810-272.
 (a)Deleted.
C.Installation
WARNING:
REFER TO THE PRODUCT LABEL AND THE MANUFACTURERS (MATERIAL) SAFETY DATA SHEET FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND PROPER USE OF THIS PRODUCT.
(1)Clean any graphite grease from the 11C4272 extension fixture and 11C3423 coupling nut torque fixture with a C10-182 cleaning cloth moist with C02-019 engine oil or C02-023 engine oil.
WARNING:
REFER TO THE PRODUCT LABEL AND THE MANUFACTURERS (MATERIAL) SAFETY DATA SHEET FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND PROPER USE OF THIS PRODUCT.
(2)Continue to clean to remove any residual graphite grease from the 11C4272 extension fixture and 11C3423 coupling nut torque fixture with a C10-182 cleaning cloth moist with C04-003 acetone.
(3)Conduct a close visual inspection to verify that the cleaning has removed all the graphite grease to prevent contamination.
(4)Install the new or repaired mid fan shaft (1, Figure 1) and new forward lock nut (2, Figure 1). Refer to the GEnx-1B EM, 72-00-04, ASSEMBLY 001, Subtask 72-00-04-430-066, and as follows:
(a)Clean the mating surfaces of the new mid fan shaft (1) and the new forward lock nut (2) as follows:
WARNING:
REFER TO THE PRODUCT LABEL AND THE MANUFACTURERS (MATERIAL) SAFETY DATA SHEET FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND PROPER USE OF THIS PRODUCT.
1Use C04-003 acetone to clean the new forward lock nut (2).
WARNING:
REFER TO THE PRODUCT LABEL AND THE MANUFACTURERS (MATERIAL) SAFETY DATA SHEET FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND PROPER USE OF THIS PRODUCT.
2Use C04-003 acetone to clean the threads of the new mid fan shaft (1).
(b)Install the new forward lock nut (2). Refer to the GEnx-1B EM, 72-00-04, INSTALLATION 001, Subtask 72-00-04-420-168, and as follows:
WARNING:
REFER TO THE PRODUCT LABEL AND THE MANUFACTURERS (MATERIAL) SAFETY DATA SHEET FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND PROPER USE OF THIS PRODUCT.
1Lubricate the thread of the new mid fan shaft (1) and the threads of the new forward lock nut (2) with C02-019 engine oil or C02-023 engine oil.
2Install the new forward lock nut (2) on the mid fan shaft (1).
3Torque the new forward lock nut (2) as follows:
aApply an initial torque of 1100-1260 lb ft (1491-1708 N.m) to the lock nut (2).
bApply a final torque to the new forward lock nut (2) as follows:
CAUTION:
DO NOT APPLY MORE THAN 24 DEGREES OR 8,300 LB FT (11253 N.M) OF TORQUE OR DAMAGE TO THE ENGINE PARTS CAN OCCUR.
(1)Torque the new forward lock nut (2) another 20 degrees past the initial torque.
Forward Lock Nut and Mid Fan Shaft Removal/Installation
Figure 1   (Sheet 1)
Forward Lock Nut and Mid Fan Shaft Removal/Installation
Figure 1   (Sheet 2)