S&S Cycle Big Twin Oil Pump Kits - Manual (Page 5)

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31-6250 Fits 1936 to 1972 1,2,3,7,8,9,10 4 (1948 to 1969 only) §
31-6251 Fits 1936 to 1972 1, 2, 3, 7, 8, 9, 10 4 (1948 to 1969 only) §
31-6252 Fits 1970 to 1991 1, 3, 7, 8, 9, 10
31-6253 Fits 1992 and Later ‡ 1, 7, 8, 9, 10
31-6254 Fits 1948-1953 1, 7, 8, 9, 10 4 §
31-6255 Fits 1954 to 1969 1, 7, 8, 9, 10 4 §
31-6256 Fits 1970-1977 1, 2, 3, 7, 8, 9, 10 5
31-6257 Fits 1978 to 1991 1, 3, 7, 8, 9, 10
31-6258 Fits 1992 & Later (Pre '89 shaft) 1, 7, 8, 9, 10
31-6259 Fits 1970-1972 1, 2, 3, 6, 7, 8, 9, 10 5 §
31-6260 Fits 1970 to 1991 1, 2, 3, 6, 7, 8, 9, 10 5 ( 1970 to 1972 only) §
31-6261 Fits 1992 and Later 1, 7, 8, 9, 10
31-6262 Fits 1970 to 1972 1, 2, 3, 6, 7, 8, 9, 10 5 §
31-6263 Fits 1948 to 1953 1, 7, 8, 9, 10 4 §
31-6264 Fits 1954 to 1964 1, 7, 8, 9, 10 4 §
31-6265 Fits 1965 to 1969 1, 6, 7, 8, 9, 10 4 §
31-6266 Fits 1970 to 1977 1, 2, 3, 6, 7, 8, 9, 10 5 (1970 to 1972 only) §
31-6267 Fits 1977 to 1991 1, 3, 7, 8, 9, 10
31-6269 Fits 1992 and Later‡ 1, 7, 8, 9, 10
31-6270 Fits 1965 to 1969 † 1, 6, 7, 8, 9, 10 4 §
31-6272 Fits 1965 to 1969 1, 6, 7, 8, 9, 10 4 §
All S&S oil pump kits are listed with the specific year
groups they fit followed by steps required for proper
installation. Select kit part number that corresponds to kit
purchased and follow required steps.
NOTES
● Perform only those steps required for oil pump kit
you will install. Installation steps vary between kits and
year groups. S&S urges you to review installation steps
for your oil pump and year group several times before
beginning installation or performing any crankcase
modifications!
● Optional steps will update 1948-1962 and 1966-1972
crankcases to 1973-later style oiling. Step 4 applies to
all 1948-1969 crankcases except 1963-1965 models.
Step 5 applies to 1970-1972 crankcases. Both
procedures separate oil supplied to top and bottom ends
to increase oil pressure to hydraulic lifters and top end.
This helps prevent hydraulic lifers from collapsing at low
RPM. While these two steps are not mandatory, S&S
strongly recommends them for all engines using
hydraulic lifters except 1963-1965 outside oiler
Panheads. It is also suggested that optional S&S high
speed oil pump drive gears be used in all 1972 and earlier
engines except Knuckleheads.
CAUTION - Failure to perform all required steps may result in
engine damage.
1. Disassembly and Crankcase Identification
All Years.
A. Remove old oil pump and mounting studs or bolts
from crankcase.
B. Identify crankcases by comparing them to those
in photo. See Picture 7. Circle year group that
matches your crankcases.
NOTES
● Proper identification of crankcase is imperative to insure
correct assembly.
● Machining of some aftermarket crankcases may not
be consistent with that of a specific stock year group. If in
doubt about modifications required for aftermarket
crankcases, contact crankcase manufacturer.
● S&S crankcases require no modification for S&S oil
pump. S&S 1936-1969 generator style cases are machined
to accept S&S or stock cast iron or early alloy pump. S&S
1970-later alternator style crankcases are machined for
1981-1991 or 1992-up oil pumps as specified at time of
order. Both S&S and stock oil pump for specific year group
can be installed without modification.
Chart 2
Kit Part No. Year Group Required Steps Optional Steps
§ S&S recommends this optional step be performed if hydraulic lifters are used.
† Installation of this kit requires use of 1973-later breather gear such as S&S part #33-4239 or #33-4251 to provide oil to primary chain. Kits #31-6260
and #31-6270 include neither of these breather gears. Be sure correct year breather gear, cam gear and pinion gear combination is used.
‡ Kit contains S&S #33-4232 pinion shaft pump drive gear which is designed to fit S&S 1981 and later style tapered pinion shaft and stock 1981-1989
style tapered pinion shaft. Engines using 1990-later style straight pinion shaft must use stock pinion shaft oil pump drive gear.