EXPORT CONTROLLED Rolls-Royce
COMMERCIAL ENGINE BULLETIN
H. Tooling -- Not applicable
I. Weight and Balance
Engine weight will decrease by 0.679 lbs. (X.XX Kgs) at engine station X.XX in. (XXX mm)
when you incorporate this bulletin.
J. Electrical Load Data -- Not affected
K. References
(1) Advance Engineering Memorandum (AEM), CW 2558
(2) Advance Engineering Memorandum (AEM), CW 5429
(3) Advance Engineering Memorandum (AEM), CW 5452
NOTE: The document above is referenced for the internal use of Rolls-Royce only.
(4) Installation Bulletin 1012.
L. Other Publications Affected -- None
M. Prerequisites -- None
2. ACCOMPLISHMENT INSTRUCTIONS
A. Remove the Spare accessory Drive Gear.
NOTE: During disassembly comply with appropriate removal, disassembly, cleaning,
inspection, removal of coating, plating, assembly and installation procedures (Ref
O/H).
REF. FIG. 1
REF. FIG. 2
REF. FIG. 3
(1) Separate the engine compressor, gearbox and turbine modules.
(2) Disassemble the gearbox (Ref. O/H, OMM).
(3) Delete Spare Accessory Drive Gear (Vacuum/Hydraulic Pump) from Power and Accessory
Gearbox (6894171, 6886442, 6898571, 6877180 or 6875492) (Ref. Fig. 1 and 2).
(4) Do not install the following parts comprising the spare accessory drive gear installation
during assembly at overhaul or in the field when access to the interior of power and
accessory gearbox has been achieved.
Part No. Nomenclature Qty
AN104620 Bolt, No. 10--32 x 1.250 lg. 1
MS16625--4112 Ring, Retaining Internal 1
6810421 Washer, Key 1
6820291 Ring, Retaining, Internal 1
6820586 Shaft, Support Idler Gear 1
6820588 Washer, Keyway Brg. Retaining 1
6824964 Spacer, Sleeve Gearshaft Brg. 1
February 1, 1980
Revision 5
November 21, 2011 M250--C20 Series CEB --1165
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EXPORT CONTROLLED COMMERCIAL ENGINE
BULLETIN
GEARBOX -- SPARE ACCESSORY DRIVE GEAR
(VACUUM/HYDRAULIC PUMP) REMOVE
1. PLANNING INFORMATION
A. Effectivity
(1) Engines
(a) All Rolls-Royce M2509 --C20R that were modified to add the spare drive gear per
IB--4006.
(b) All Rolls-Royce M250--C20 and --C20B series engines and power and accessory
gearboxes prior to:
Model No. Engine S/N Gearbox S/N
M250--C20 CAE 823568 CAG 34583
M250--C20B CAE 832105 CAG 35239
NOTE: The engine serial numbers above are based on current production records.
(2) Spares -- Not affected
B. Reason
The Spare Accessory Drive (Vacuum/Hydraulic Pump) is considered redundant if the drive is
not used on the Power and Accessory Gearboxes (6894171, 6886442, 6898571, 6877180 and
6875492).
C. Description
The Spare Accessory Drive Gearshaft Assembly (6854852), its associated idler gear and
bearings, shaft seal, bearing cage and retaining pin and other detail parts of the installation, can
be removed from the gearbox cover assembly at customer option.
D. Approval
Technical aspects are FAA approved.
E. Compliance
Compliance Code 7: To be complied with per customer option.
F. Interchangeability
Not affected, except where the users special application requires installation of the spare
accessory drive gear.
NOTE: Installation of parts to activate the spare accessory drive is defined in M250--C20
Series Installation Bulletin 1012.
G. Material Availability -- Not applicable
February 1, 1980
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November 21, 2011 M250--C20 Series CEB --1165
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COMMERCIAL ENGINE BULLETIN
6824977 Gear, Spur 1
6840109 Retainer, Bearing 1
6840380--98 Ring, Retaining 1
6854424 Seal, Plain Encased 1
6854852 Gearshaft Assy. 1
6823977 Plug 1
6859431 Bearing, Ball Annular 1
6859432 Bearing, Ball Annular 2
CAUTION: BECAUSE OF THE COMPLEX MACHINING NECESSARY TO REMOVE THE
RETAINING PIN AND BEARING CAGE, THE STEPS THAT FOLLOW MUST BE
DONE AT A ROLLS-ROYCE AUTHORIZED OVERHAUL/REPAIR FACILITY.
DAMAGE TO THE PART CAN OCCUR.
B. Remove bearing cage, its retaining pin and the spring pin (MS9047--065) at the gearbox cover
assembly spare accessory drive pad. (Ref. Fig. 3).
(1) Do step 2. B. at the same time with step 2. A. If an older version of CEB 1165 was
completed and the bearing cage and its associated parts was not removed, then do step
2.B. at the next time the gearbox is opened.
(2) Do a 200 hour inspection, on the engines with the bearing cage still installed, for a loose
bearing case or retaining pin. If the bearing cage or the retaining pin is loose than do step
2.B. immediately.
Part No. Nomenclature Qty.
6843363 Bearing Cage 1
MS9486--01 Pin 1
MS9047--065 Spring Pin 1
C. Reidentify the part.
(1) Use the vibro--peen and method 2D1 or 2E (Ref. 70--01--05, EMM) to write the CEB
number (CEB 1165) directly below the Gearbox Cover Assembly Part No. Paint
vibro--peened area per AMS 2510 using AMS 2475 treatment.
(2) If service reidentifying the power and accessory gearbox cover assembly, use the
vibro--peen and method 2Dl or 2E (Ref. 70--01--85, EMM) to write a line through previous
part number, write the new part number adjacent to previous number, and write the CEB
number (CEB 1165) directly below the new Gearbox Cover Assembly Part Number. Paint
vibro--peened area per AMS 2510 using AMS 2475 treatment.
D. Comply with power and accessory gearbox assembly and test procedures (Ref. OMM).
E. Record compliance with this commercial engine bulletin in the applicable section of the engine
logbook, gearbox assembly, Part III, Modification Record as applicable with the following:
M250--C20, --C20B Series CEB 1165
F. Basis for quantities is per gearbox assembly.
February 1, 1980
Revision 5
November 21, 2011 M250--C20 Series CEB --1165
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COMMERCIAL ENGINE BULLETIN
Gearbox, Spare Accessory Drive Gear (Vacuum/Hydraulic Pump) Remove
FIG. 1
February 1, 1980
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November 21, 2011 M250--C20 Series CEB --1165
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COMMERCIAL ENGINE BULLETIN
Gearbox, Spare Accessory Drive Gear (Vacuum/Hydraulic Pump) Remove
FIG. 2
February 1, 1980
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November 21, 2011 M250--C20 Series CEB --1165
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COMMERCIAL ENGINE BULLETIN
Must be Removed When Parts Listed in Fig. 2 are removed.
Gearbox, Spare Accessory Drive Gear Components
FIG. 3
February 1, 1980
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COMMERCIAL ENGINE BULLETIN
3. MATERIAL INFORMATION
A. Configuration Chart
QTY/ QTY/ INSTRUCTIONS/
NEW P/N ENG NAME OLD P/N ENG DISPOSITION
6894171 1 Gearbox Assy (--C20B) 6894171 1 1
6886442 Alt Gearbox Assy (--C20B) 6886442 Alt 1
6898571 1 Gearbox Assy (--C20) 6898571 1 1
6877180 Alt Gearbox Assy (--C20) 6877180 Alt 1
6875492 -- Gearbox Assy (--C20) 6875492 Alt 1
23057100 Alt Cover Assy, Power & 23032286 Alt 1
Accessory
-- -- E Bolt, No. 10--32 x 1.250 lg AN104620 1 2
-- -- E Ring, Retaining, Internal MS16625--4112 1 2
-- -- E Washer, Key 6810421 1 3
-- -- E Ring, Retaining, Internal 6820291 1 2
-- -- E Shaft, Support 6820586 1 2
Idler Gear
-- -- E Washer, Keyway Brg. 6820588 1 2
Retaining
-- -- E Spacer, Sleeve 6824964 1 2
Gearshaft Brg.
-- -- E Gear, Spur 6824977 1 2
-- -- E Retainer, Bearing 6840109 1 2
-- -- E Ring, Retaining 6840380--98 1 2
-- -- E Seal, Plain Encased 6854424 1 3
-- -- E Gearshaft Assy 6854852 1 2
-- -- E Plug 6823977 1 2
-- -- E Bearing, Ball Annular 6859431 1 2
-- -- E Bearing, Ball Annular 6859432 2 2
-- -- E Pin, Spring MS9047--065 1 2
-- -- E Pin, Retaining MS9486--01 1 2
-- -- E Cage, Bearing 6843363 1 2
INSTRUCTIONS/DISPOSITION NOTES
1. Modify at customers discretion.
2. Remove and if serviceable, return to stores for possible reuse in other location.
3. Scrap.
CUSTOMER SUPPORT
ROLLS-ROYCE
February 1, 1980
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