S&S Cycle Big Twin Oil Pump Kits - Manual (Page 3)

3
● Powder Coating - In our experience, subjecting heat-
treated alloys such as those used in S&S oil pumps,
crankcases, cylinder heads and other parts to excessive
heat can drastically alter their hardness, strength and other
critical properties. The degree to which these properites
are altered depends upon the temperatures reached and
the duration of exposure. When powder-coating or
otherwise processing alloy parts, S&S exposes them to a
maximum temperature of 370
°
F for no longer than 20
minutes. Under no circumstances should parts be heated
past 400
°
F!
S&S oil pump bodies and covers are also chemically
treated to insure proper function. Excessive heat may alter
treatment compounds resulting in poor pump performance
and extensive engine damage due to insufficient
lubrication.
CAUTION - Plating or otherwise altering S&S oil pump
may cause irreversible damage and interfere with
engine lubrication. Damages associated with
modified S&S oil pump will not be covered under
warranty.
● There are important differences in internal machining
of oil pump bodies for each kit. Before beginning
installation, compare pump body you received with those
in Pictures 1, 2 & 3. Pump bodies are designed for specific
year groups and must not be interchanged or installed on
engines other than those they were designed for.
● Cast pump body #31-6003 for 1970-1991 models is
identical to #31-6006 body for 1992-up models except
for slightly different mounting bolt patterns. To positively
identify bolt pattern, place known oil pump gasket against
pump body and note whether lower bolt holes in gasket
and body line up. Parts can also be identified by measuring
thickness of material between bottom right bolt hole and
supply gear cavity. See Picture 4. Measurement for 1991-
earlier pattern is approximately 080”. Measurement for
‘92-up pattern is approximately .150”.
● Oil pump covers for 1992-up engines are machined
differently from covers for earlier engines. 1992-up covers
have slightly different bolt pattern, no provision for rear
chain oiler, and slotted lower left bolt holes. To identify
cast covers, compare cover you received to covers in
Picture 5.
● Billet pump covers have essentialy the same
differences as cast covers as well as additional options
for oil line fitting placement. Billet covers #31-6044 and
#31-6047 have 1992-up mounting hole pattern. Billet
covers #31-6041 and #31-6045 have ‘91-earlier mounting
bolt pattern. See Picture 6. Additional information
regarding billet covers can be found on pages 11 & 12.
Chart 1
Pump Kit Pump Pump Drive Shaft Pinion Shaft Breather
Part No. Body Cover Drive Gear Drive Gear Gear Kit
Part No. Part. No. Part No. Part. No. Part No.
31-6250 31-6001 31-6002
31-6260 31-6003 31-6002
31-6270 31-6073 31-6002
31-6262 31-6003 31-6002 33-4239
31-6272 31-6073 31-6002 33-4239
31-6263 31-6001 31-6002 33-4230 33-4237§ 33-4239
31-6264 31-6001 31-6002 33-4230 33-4232 33-4239
31-6265 31-6073 31-6002 33-4230 33-4232 33-4239
32-6266 31-6003 31-6002 33-4230 33-4232 33-4239
31-6267 31-6003 31-6002 33-4230 33-4232‡ 33-4250†
31-6261 31-6006 31-6039
31-6269 31-6006 31-6039 33-4230 33-4232‡ 33-4250†
31-6251 31-6040 31-6041
31-6252 31-6042 31-6041
31-6253 31-6043 31-6044
31-6254 31-6040 31-6041 33-4230 33-4237 33-4239
31-6255 31-6040 31-6041 33-4230 33-4232 33-4239
31-6256 31-6042 31-6041 33-4230 33-4232 33-4239
31-6257 31-6042 31-6041 33-4230 33-4232 33-4250
31-6258 31-6043 31-6044 33-4230 33-4232 33-4250
31-6259 31-6042 31-6041 33-4239
§ Pinion shaft drive gear, part #33-4237 for 1939 to 1953 engines, is
easily distinguishable from 1954 and later gears by the inside diameter
splines machined to fit early style splined pinion shafts.†
† Breather valve gear kit, part #33-4250 for 1977 and later engines, has
a different pitch diameter from 1977 and earlier gears and can be
identified by a circular groove machined in the gear face.
‡ #33-4232 pinion shaft pump drive gear is designed to fit S&S 1958
and later style tapered pinion shaft and stock 1954 to 1989 style
tapered pinion shaft. Engines using stock 1990 and later style straight
pinion shaft must use stock pinion shaft oil pump gear.
Note: "Bold type indicates billet oil pump kits."
Picture 5
#31-6041
#31-6044
#31-6045
#31-6047