Warning – S&S Cycle Big Twin Engines with 3-1/2 and 3-5/8 Bore Crankcases and Special Application (SA) 4 Bore Crankcases User Manual

Page 4

6. Lubricate pinion bearing and pinion shaft bearing boss with

petroleum jelly. Install bearing and secure with pinion shaft
main bearing snap ring. See Picture 6 on previous page.

NOTE - Pinion and sprocket shaft bearings should be correct sizes,
but it is engine builder’s responsibility to confirm flywheel
endplay, connecting rod sideplay, bearing fit, and all clearances
in unassembled engine at time of assembly. It is of particular
importance to check flywheel endplay and install different
Timken

bearing spacer if necessary. Refer to Harley-Davidson

Service Manual for detailed explanation of required procedure.

NOTE - Harley-Davidson

has used different style pinion bearings

in various models, some requiring different snap rings. Snap ring
supplied by S&S

or identical replacement must be used with

pinion bearing supplied in S&S engine.

NOTE - Ends of snap ring are rounded on one side, sharp on the
other. Install snap ring with sharp edge out, away from flywheels.

ASSEMBLE CRANKCASE HALVES

Gasoline, lacquer thinner, and many solvents are extremely
flammable. Fumes may be explosive and toxic if inhaled.
Read and follow the manufacturers’ instructions if applicable,
and use these materials only in a well ventilated area away
from sparks and open flame.

Wipe down mating gasket surfaces of crankcase halves with
lacquer thinner. Remove residue with clean, dry cloth, then
apply sealant of choice to pinion side crankcase. Take care to
avoid breather cavity and other areas where sealant might
reach inside of engine. See Picture7. Coat right main
bearing race with petroleum jelly. If applicable, allow sealant
to cure according to manufacturer’s instructions, then join
left and right crankcase halves.

NOTE - In most instances S&S uses Hylomar

or Threebond

1104

to seal crankcase. Use any sealant carefully to prevent excess
from entering engine and obstructing oil passages or
contaminating oil supply.

2. Install crankcase studs and washers according to

crankcase instructions.

Note - Alignment studs for S&S generator and alternator
crankcases are in same locations B, E, & G. See Diagram 1. They
must be installed before other studs and bolts. Fit is tight, so
alignment studs must be lubricated with assembly lube, then
tapped through case assembly with plastic mallet.

3. Tighten 5/16” case bolts and studs to 15-18 ft-lbs, 1/4” center

bolt to 10-12 ft-lbs. See Diagram 1 for identification, and
tighten fasteners in following sequence: G-B-E-F-H-D-C-A.

4. Install drive sprocket spacer and sprocket shaft oil seal in

main bearing race of left case.

NOTE - Because of semi-dry primary housing in shovelheads and
sealed, wet primary in big twin models, S&S installs shovelhead
sprocket shaft seals with spring facing inside, big twin seals with
spring out. See Picture 8.

5. Allow crankcase sealant to cure per mfr.’s instructions, then

pour four ounces of motor oil over bearing end of
connecting rod assembly and into flywheel cavity. Rotate
flywheels several times to distribute oil over connecting rod
bearings. Assembly should turn freely and without binding.

Picture 7

Picture 8 (Big Twin Models)

Diagram 1

WARNING