1.PLANNING INFORMATION
A.Effectivity
* * * FOR GEnx-1B54, -1B58, -1B64, -1B67, -1B70
This Service Bulletin has been introduced in production to these GEnx-1B engines:
•
GEnx-1B engines, serial numbers 956-132 and up.
These serial numbers are the best available data.
The old A/O vent center tube P/N 2331M21G01 is affected by this Service Bulletin.
B.Description
This Service Bulletin releases a new A/O vent center tube P/N 2331M21G02 that removes features from the inner flowpath to reduce oil retention.
C.Compliance
Category 7
GE recommends that you do this Service Bulletin at customer's option.
NOTE:
This Service Bulletin can be accomplished in shop.
D.Concurrent Requirements
None.
E.Reason
(1)Objective:
To improve maintainability.
(2)Condition:
Oil retention has been observed in the A/O vent center tube post engine shutdown.
(3)Cause:
The A/O vent center tube inner tab creates a damming feature in the flowpath, this prevents the oil from draining at engine shutdown.
(4)Improvement:
The A/O vent center tube inner tab feature is removed.
(5)Substantiation:
Substantiation is by 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.
G.Manpower
An estimate of the labor cost to accomplish this Service Bulletin may be obtained from any GEnx-1B GEAE authorized Service or Overhaul facility upon request.
H.Weight and Balance
The complete compliance with this Service Bulletin decreases weight by 0.02 lb (0.009 kg).
I.References (Use the latest version of these documents)
GEK 112851, GEnx-1B Engine Manual (EM)
GEK 112864, GEnx-1B Engine Illustrated Parts Catalog (EIPC)
NOTE:
The reference document listed below is for the engine manufacturer's internal use only:
 
CID: 942531
J.Publications Affected
GEK 112864, GEnx-1B Engine Illustrated Parts Catalog (EIPC)
K.Interchangeability
Two-way interchangeable.
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
 
2331M21G02
(1)
Tube, A/O Vent Center
Quote
(-)
Quote
 
2331M26P01
(4)
Insert, Locking
Quote
(-)
Quote
 
M83248/1-143*
(3)
Packing, Preformed
NP
(-)
--
 
2331M93P01
(1)
Packing, Preformed
Quote
(-)
Quote
 
NP= not provisioned
 
*Part not supplied by GE Engine Services Distribution L.L.C. Procure through local purchase.
NOTE:
Prices are provided for planning purposes and are subject to change.
(2)Other Spare Parts:
None.
(3)Consumables:
None.
B.Industry Support Information
None.
C.Configuration Chart
 
New Part Number
Qty/ Eng
Part Name
Old Part Number/ IPC Location
Qty/ Eng
Op Code
Chg/ Sprt Code
 
2305M64G02
(X)
Shaft, Mid Fan
2305M64G02
(X)
RM
-/-
 
.2331M21G02
01-020A, 72-58-00
(1)
Tube, A/O Vent Center
.2331M21G01
01-020, 72-58-00
(1)
RE
2/B
Operation Codes
RM=Remains
RE=Replace
Change Code
2=Two-way interchangeable.
Support Code
B=Old parts will be supplied until all old parts are sold.
D.Parts Disposition
Use serviceable old parts for engines that have not changed.
E.Tooling - Price and Availability
None.
3.ACCOMPLISHMENT INSTRUCTIONS
A.General
(1)Remove the low pressure turbine (LPT) module assembly and the mid fan shaft assembly from the propulsor assembly. Refer to the GEnx-1B EM, 72-00-04, REMOVAL 001.
(2)Disassemble the LPT module assembly and the mid fan shaft assembly. Refer to the GEnx-1B EM, 72-00-04, DISASSEMBLY 001.
(3)Remove the old A/O vent center tube (1, Figure 1). Refer to the GEnx-1B EM, 72-58-00, DISASSEMBLY 001, Subtask 72-58-00-030-002.
(4)Install the new A/O vent center tube (1, Figure 1). Refer to the GEnx-1B EM, 72-58-00, ASSEMBLY 001, Subtask 72-58-00-440-009.
(5)Assemble the LPT module assembly and the mid fan shaft assembly. Refer to the GEnx-1B EM, 72-00-04, ASSEMBLY 001.
(6)Install the LPT module assembly and mid fan shaft assembly to the propulsor assembly. Refer to the GEnx-1B EM, 72-00-04, INSTALLATION 001.
A/O vent center tube Installation
Figure 1