ENGINE, ACCESSORY GEARBOX ASSEMBLY, CENTRIF~UGAL BREATHER GEAR,
IMPROVED CONFIGURATION
1. PLANNING INFORMATION:
A. Effectivity:
All Allison 250-C18, CZO, C20R, B15, B17, and B17F Series engines are
affected by this Bulletin as follows:
Model Serial
___- Number
250-Cl8 Series All are affected
250.C2OB CAG 22500.23027
CAG 40000-40939
CAG 27001-27434
CAG 23700-23810
250.C2OS CAG 10000-10034
250-C20R Series CAG 15001-15215
All are affected
CAG 80001-80729
CAG 81001-81006
B. Reason:
An improved efficiency breather gear which reduces the oil spew rate has
been released to the Model 250 Series I and Series II engines. This
bulletin releases the new breather gear (P/N 23038229).
C. Descriotion:
An additional eight holes have been added to the existing eight holes (16
total) in the Idler Spur Gearshaft (Centrifugal Breather Gear) to reduce
the oil spew rate. This bulletin changes the P/N of the Idler Spur
Gearshaft from P/N 6889094 to P/N 23038229.
D. Approval: Technical aspects are FAA approved.
E. Compliance:
Compliance Code 7. To be complied with per customer option.
F. Interchanqeabilitv: Not affected.
January 31, 1989 250-Cl8 Series CEB 257
Revision No. 1 250.C20 Series CEB 1266
June 15, 1994 250.C20R Series CEB 72-4009
250-615 Series TP CEB 132
250-817 Series TP CEB 1225
250-B17F Series TP CCB 72-2009
Page 1 of 5
Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
Allison Engine Company
Commercial Engine Bulletin
1. PLANNING INFORMATION: (Continued)
G. Material Availabilitv:
New-Part No. Nomenclature !zY
23038229 Gearshaft, Spur- 1
Gasifier Train Idler
H. Toolinq: None.
I. Weight and Balance: Not affected.
J. Electrical Load Data: Not affected.
K. References:
AEM CW 4657-A, 4580
L. Other Publications Affected:
(1) 5W2 Operation and Maintenance Manual, Turboshaft Models 250-C18A,
-C18B, -C18C
(2) 5W3 Overhaul Manual, Turboshaft Models 250-C18A, -C18B, -C18C
(3) 5W4 Parts Catalog, Turboshaft Models 250.C18A, -C18B, -C18C
(4) 6W2 Operation and Maintenance Manual, Turboprop Model 250-8156
(5) 6W3 Overhaul Manual, Turboprop Model 2%B15G
(6) 6W4 Parts Catalog, Turboprop Model 250-8156
(7) lOW2 Operation and Maintenance Manual, Turboshaft Models 250.C20,
-C2OB, -C2OF, -C2OJ
(8) lOW2S Operation and Maintenance Manual, Turboshaft Models 250-C2OS
(9) lOW3 Overhaul Manual, Turboshaft Models 250.C20, -C2OB, -C2OF, -C2OJ
(10) lOW3 Supplement A, Overhaul Manual Supplement, Turboshaft Model
250.C2OS
(11) lOW4 Parts Catalog, Turboshaft Models 250.C20, -C2OB, -C2OF, -C2OJ
January 31, 1989 250.Cl8 Series CEB 257
Revision No. 1 250.C20 Series CEB 1266
June 15, 1994 250.C20R Series CEB 72-4009
250-815 Series TP CEB 132
250-817 Series TP CEB 1225
250.B17F Series TP CEB 72-2009
Page 2 of 5
Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
Allison Engine Company
Commercial Engine Bulletin
1. PLANNING INFORMATION: (Continued)
(12) lOW4S Parts Catalog, Turboshaft Model 250.C2OS
(13) llW2 Operation and Maintenance Manual, Turboprop Models 250-817,
-8178, -B17C, -8170, -B17E
(14) llW3 Overhaul Manual, Turboprop Models 250-817, -8178, -B17C, -B17D,
-617E
(15) llW4 Parts Catalog, Turboprop Models 250.B17, -9176, -B17C, -B17D,
-B17E
(16) GTP 5232-2 Operation and Maintenance Manual, Turboshaft Model
250.C20R
(17) GTP 5232-3 Overhaul Manual, Turboshaft Model 250.C20R
(18) GTP 5232-4 Illustrated Parts Catalog, Turboshaft Model 250.C20R
(19) GTP 5243-2 Operation and Maintenance Manual, 'Turboprop Model
250-617F
(20) GTP 5243-3 Overhaul Manual, Turboprop Model 250.B17F
* (21) GTP 5243-4 Illustrated Parts Catalog, Turboprop Model 250.BI7F
* NOTE 1. Not published as of January 31, 1989
M. Prereauisites:
250-Cl8 Series CEB 228 and CEB 243
250-C20 Series CEB 1201 and CEB 1228
250-B15 Series TP CEB 98 and TP CEB 112
250-817 Series TP CEB 1162 and TP CEB 1185
January 31, 1989 250-Cl8 Series CEB 257
Revision No. 1 250.C20 Series CEB 1266
June 15, 1994 250-C20R Series CEB 72-4009
250.B15 Series TP CEB 132
250-817 Series TP CEB 1225
250-B17F Series TP CEB 72-2009
Page 3 of 5
Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
ALLISON ENGINE COMPANY
Commercial Engine Bulletin
2. ACCOMPLISHMENT INSTRUCTIONS:
A. All removal and disassembly operations must be done in accordance with
the-appropriate Operation and Maintenance Manual.
B. Remove gearbox module from the engine.
C. Separate the gearbox module.
CAUTION: USE CARE SO THAT THE BEARINGS ARE NOT DAMAGED DURING THEIR REMOVAL
AND REINSTALLATION.
D. Remove P/N 6889094, Idler Spur Gearshaft, and replace with P/N 23038229.
E. Remove and replace the Breather Gear Lip Seal P/N 6856211.
F. Reassemble the gearbox.
G. Reassemble the engine.
H. Record compliance in the Engine Log Book, Gearbox Assembly (yellow
pages), Part III, Modification Record, as applicable with the following:
250.Cl8 Series CEB 257
250-C20 Series CEB 1266
250.C20R Series CEB 72-4009
250.B15 Series TP CEB 132
250.B17 Series TP CEB 1225
250-B17F Series TP CEB 72-2009
January 31, 1989 250.Cl8 Series CEB 257
Revision No. 1 250.C20 Series CEB 1266
June 15, 1994 250.C20R Series CEB 72-4009
250-815 Series TP CEB 132
250.B17 Series TP CEB 1225
250-B17F Series TP CEB 72-2009
Page 4 of 5
Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
ALLISON ENGINE COMPANY
Commercial Engine Bulletin
3. MATERIAL INFORMATION:
A. Basis for quantities is per gearbox assembly.
B. Bill of material:
Instructions/
New P/N QLY Nomenclature Old P/N QQ Disposition
23038229 1 Gearshaft, Spur- 6889094 1 1,2
Gasifier Train
Idler
6856211 1 Seal, Plain Encased 6856211 1 2
INSTRUCTIONS/DISPOSITION NOTES:
1. New Item.
2. Remove and replace.
CUSTOMER SUPPORT
ALLISON ENGINE COMPANY
January 31, 1989 250-Cl8 Series CEB 257
Revision No. 1 150.C20 Series CEB 1266
June 15, 1994 150.CZOR Series CEB 72-4009
250-B15 Series TP CEB 132
250.B17 Series TP CEB 1225
250-817F Series TP CEB 72-2009
Page 5 of 5
Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
