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BIG TWIN
1984-99 Big Twin Pinion Hardware
1984-99 Big Twin Pinion Hardware
VT No. 
OEM 
Year/Item
12-1184 
275 
1970-up Bushing Pin
12-1153 
358 
1970-up Dowel Pin
8761-7 
Kit 
1970-92 Chrome Allen Screw Set
9305-7 
Kit 
1970-92 Stock Chrome Screws
9306-7 
Kit 
1970-92 Stock Cadmium Screws
9633-50 
6099 
14 
1970-up Washer, Chrome
12-0316 
9058 
18 
1970-up Needle Bearing
37-8971 
10046 
19 
1981-up Wire Clamp
12-0901 
11002 
20 
1970-up Oil Pump Retainer Ring
12-0202 
23985-54 
23 
1970-up Key, Gear Shaft 
Note: 
24/26  See Chart for Pinion Gear Listing
12-0507 
24023-54 
25 
1970-89 Pinion Gear Nut
12-0613 
As Above 
 Jims
12-0512 
24022-90 
25 
1990-92 Pinion Gear Nut
12-0577 
7916A 
25 
1993-up Pinion Gear Nut
10-0703 
24641-36 
28 
1970-up Oil Pump Shaft Bush
12-1539 
24703-54B 
29 
1970-89 Pinion Gear Spacer
12-9922 
24704-90 
29 
1990-up Pinion Gear Spacer
15-0871 
25225-70B 
33 
1970-92 Gasket and Seal Kit
15-0872 
25225-93 
33 
1993-up Gasket and Seal Kit
12-9906 
25313-77 
38 
1978-99 Breather Valve, S&S
12-9957 
    –– 
38 
As Above .030 O.S.
12-9909 
S&S 
37 
Washers for Above (Set)
12-1537 
25313-77 
38 
1978-99 Breather Gear, Sifton Steel
12-1531 
25310-82 
38 
1982-90 1992-up Breather Valve(Plastic)
12-1530 
Nylon 
39 
1982-up .130-.165 Set, 8 pack
12-1533 
25329-91 
39A  1991-up Big Twin Air/Oil Separator
12-1508 
25550-36 
43 
1970-up Cam Gear
 
 
Washer Set  
  
.050-.095 (10 pieces)
10-1254 
25550-84 
43 
1984-up .045 Thick, 5 pack
12-1440 
   –– 
43 
.050 Cam Gear Washer
12-1441 
   –– 
43 
.055 Cam Gear Washer
12-1425 
   –– 
43 
.060 Cam Gear Washer
12-1426 
   –– 
43 
.065 Cam Gear Washer
12-1427 
   –– 
43 
.070 Cam Gear Washer
12-1428 
   –– 
43 
.075 Cam Gear Washer
12-1429 
   –– 
43 
.080 Cam Gear Washer
12-1430 
   –– 
43 
.085 Cam Gear Washer
12-1431 
   –– 
43 
.090 Cam Gear Washer
12-1432 
   –– 
43 
.095 Cam Gear Washer
12-1433 
   –– 
43 
.100 Cam Gear Washer
17-0908 
25550-57 
44 
1958-up Lock Washer, 5 pack
17-1281 
25550-57A 
 45  Cam Washer, 5 pack
10-0705 
25581-70 
46 
1970-up Bushing
10-2525 
As Above 
46 
.005 Oversize
10-0708 
25582-73 
47 
1973-92 Bushing Standard
10-2529 
As Above 
47 
1973-92 Bushing .005 Oversize
10-8536 
25582-93 
47 
1993-up Bushing
10-8556 
As Above 
47 
1993-up Bushing .005 O/S
12-1407 
26345-73 
50 
1973-up Drive Gear, 24T
12-0805 
26346-70 
52 
1970-up Gear Shaft
12-0205 
26348-15 
53 
1936-up Oil Pump Key, 10 pack
12-1392 
26349-84 
54 
1984-89 Drive Gear
12-1438 
26354-90 
54 
1990-92 Drive Gear
12-1439 
26354-93 
54 
1993-up Drive Gear
12-1438
12-1439
Breather Gear
B 12-1531
B-Stock Plastic Breather Valves.
VT No.  OEM 
Year
12-1531  25310-82A L1977-99
12-1953  As Above  .005 Oversize
C-Thrust Washer Set, Breather Valve for 
1979-99 Big Twin includes one of each 
size as noted.
VT No.  Fits 
Set
12-1510  1979-82 
8 Steel
 
.110, .115, .120, .125
 
.130, .135, .140, .145
12-1530  1982-99 
8 Plastic
 
.130, .135, .140, .145
 
.150, .155, .160, .165
C 12-1510
A-Big Twin Steel 
Breather Valve
 
is a machined 
breather valve and 
gear. Designed to 
replace the stock 
steel or plastic units. 
Order 8-piece thrust washers separately. 
Available in stock duration only with either 
standard or +.030 oversize outside dimen-
sion.
VT No.  Years 
Size 
Brand
12-9906  1978-99 Standard  S&S
12-1537 1978-99 Standard  Sifton
12-9957 1978-99 +.030 
S&S
12-9909  All 
Washer Set  S&S
12-1510  All 
Washer Set  Sifton
A
Sifton
TM
 Breather 
Gear Kit is con-
structed of precision 
ground steel with 
screen installed. 8 
piece steel thrust 
washer set included. Fits 1978-85 BT.
VT No. 12-1540
S&S Reed 
Breather 
features 
three steel reeds 
that are normally 
in the closed posi-
tion. The down-
ward cylinder 
motion increases 
crankcase pressure to open the reeds. On 
the upward stroke a vacuum is created. 
VT No. 12-1949
12-1949
12-1945
Installed
12-1945
Sifton Air Ramp fits S&S/Sifton 
Breather Gear on 1936-99 models to 
remove more air and oil from crankcase. 
Requires removal of screen for installa-
tion. Gear not included.
VT No. 12-1945
Pinion Shaft Gears. Orange is largest, black is the smallest. 
Size
1977-89
OHV BT
1993-99
Evo Big Twin
Orange
12-9938
    
White
12-9943
    
Yellow
12-9945
    
Red
12-9940
12-1210
Blue
12-9941
    
Green
12-9942
    
Black
12-9939