TRANSMITTAL INFORMATION
REVISION 1 TO SERVICE BULLETIN 72-0016
Revision 1 is issued to update paragraphs 1.E. Reason and 2.D. Parts Disposition. The original was issued August 23, 2011. Revision bars in the left margin identify changes.
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 956-135 and up.
These serial numbers are the best available data.
The No. 4 cylindrical roller bearing (No. 4 roller bearing) P/N 2301M14P01 is affected by this Service Bulletin.
B.Description
This Service Bulletin releases a new No. 4 roller bearing P/N 2301M14P02 to the GEnx-1B engines.
C.Compliance
Category 4
GE recommends that you do this Service Bulletin when the No. 4 roller bearing is exposed.
NOTE:
This Service Bulletin can be accomplished in shop.
D.Concurrent Requirements
None.
E.Reason
(1)Objective:
To introduce a new part and to improve maintainability.
(2)Condition:
 The current No. 4 roller bearing has a break edge on its forward bore edge, which at some stack up conditions results in an interference between the No. 4 roller bearing and the pilot diameter of the high pressure turbine (HPT) stage 1 disk shaft. This condition has been seen during the assembly of some new engines on the bearings supplied by one of the two manufacturing sources.
(3)Cause:
The current No. 4 roller bearing break edge does not assemble correctly under critical stack up conditions.
(4)Improvement:
 The new No. 4 roller bearing incorporates a more clearly defined chamfer (in place of a break edge) that ensures, for all possible assembly tolerance stack ups, no radial or axial interference between the No. 4 roller bearing and the forward pilot diameter on the HPT stage 1 disk will occur.
 The piece part inspection of the No. 4 roller bearing P/N 2301M14P01 will verify that there is a good break edge/chamfer present for continued service.
(5)Substantiation:
Substantiation is by comparative analysis.
F.Approval
This Service Bulletin contains no modification information that revises the approved configuration and therefore does not require FAA approval.
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)
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: 547802
J.Publications Affected
GEK 112851, GEnx-1B Engine Manual (EM)
GEK 112864, GEnx-1B Engine Illustrated Parts Catalog (EIPC)
K.Interchangeability
Qualified interchangeability.
L.Software Accomplishment Summary
Not applicable.
2.MATERIAL INFORMATION
A.Material - Price and Availability
(1)Parts necessary to do this Service Bulletin:
None.
(2)Other Spare Parts:
 
Part Number
Qty/ Eng
Part Name
Unit ($) Price
Pkg Qty
Lead Time Days
 
2301M14P02
(1)
Bearing, No. 4 Cylindrical Roller
Quote
(-)
Quote
NOTE:
Prices are provided for planning purposes and are subject to change.
(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
 
2305M58G05
(X)
Turbine Center Frame Assembly
2305M58G05
(X)
RM
-/-
 
.2301M14P02
15-091, 72-54-00
(1)
Bearing, No. 4 Cylindrical Roller
(SIN 01400)
.2301M14P01
15-090, 72-54-00
(1)
RW/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
 The No. 4 roller bearings P/N 2301M14P01 with a serial number prefix beginning with FCA have a large break edge and were found not to be susceptible to either a radial or axial interference with the forward pilot diameter on the HPT stage 1 disk. These parts can be used if they are within the manual defined serviceability limits.
 The initial No. 4 roller bearings P/N 2301M14P01 with a serial number prefix beginning with FBG only had a small break edge. These bearings were found during production assembly and returned for rework.
 There should not be a No. 4 roller bearing P/N 2301M14P01 in service that does not have a good break edge. However, if piece part inspection finds a bearing with an edge/chamfer that is less than 0.040 inches (1.02 mm), do not use the bearing and contact GE for instructions on how to get the part reworked.
E.Tooling - Price and Availability
None.
3.ACCOMPLISHMENT INSTRUCTIONS
A.General
(1)Removal and installation instructions of the No. 4 roller bearing (1, Figure 1) have not changed. Refer to the GEnx-1B EM, 72-54-00, DISASSEMBLY 001 and ASSEMBLY 001.
No. 4 Roller Bearing New Configuration
Figure 1