S&S Cycle Big Twin Engines with 3-1/2 and 3-5/8 Bore Crankcases and Special Application (SA) 4 Bore Crankcases - Manual (Page 7)

NOTE - Drive gear spacer will not completely fill space between
oil pump drive gear and pinion gear. A gap of up to .125” may
exist and is normal. Engine rotation keeps oil pump gear in place
during normal operation. Spacer prevents gear and key from
becoming disengaged if engine rotated backwards.
Installing pinion gear or nut without Loctite ® can cause
damage to shaft, nut, or other parts.
3. In Generator engines only, install intermediate and circuit
breaker drive gears, and spacers if applicable.
NOTE - To increase bushing surface area, S&S ® intermediate
and circuit breaker drive gears do not utilize spacers. Correct
end play of .003-.007 in. must be established using shims
provided with gears.
Timing mark on circuit breaker drive gear must align with mark
on pinion gear. Other mark on pinion gear must be positioned
to align with mark on camshaft gear when camshaft installed.
See Picture 16A.
INSTALL BREATHER GEAR, CAMSHAFT, AND GEAR
COVER (All Unassembled)
1. Thoroughly clean and dry all parts including camshaft
lockwasher and thrust washer. Carefully inspect breather
gear for burrs and remove as necessary. Inspect edges of
crankshaft breather for burrs and smoothness. Cam thrust
washer and breather gear shims should be correct size, but
endplay of camshaft and breather gear must be verified by
customer. Refer to S&S Camshaft Instruction Sheet #51-1026,
Gear Cover Instructions #51-1032, and Harley-Davidson
®
Service Manual as necessary.
2. Apply light coat of Vaseline ® to cam bearing, and coat of
assembly lube to cam lobes, camshaft lockwasher,
thrustwasher, breather gear, and to breather gear cavity
inside engine.
3. Place camshaft lockwasher in case with ears down and flat
edge towards rear of engine. See Picture 17.
4. Install thrust washer over end of cam and place assembly in
engine. During installation, rotate engine so marks on cam
gear and pinion gear align. Second mark on cam gear must
be at eight o’clock position. In Generator engines, second
mark on pinion gear must be at two o’clock position to align
with mark on circuit breaker drive gear.
5. Install breather gear and shim, aligning breather gear timing
mark with eight o’clock mark on cam gear. See Picture 16B.
6. In Generator engines only, install breather screen and
separator (not supplied by S&S) if desired.
7. Use connecting rods to rotate flywheels and insure gears
rotate freely. Apply assembly lube to ends of shafts and
meshing surfaces of gears and remove excess.
8. Apply assembly lube to gear cover bushings.
9. Clean gasket surfaces on engine and gear cover with lacquer
thinner, wipe dry, and apply light film of Hylomar ® or
preferred sealant to both sides of gasket.
10. Install gasket and cover and tighten screws to 10-12 ft-lbs.
NOTE - Gear cover should slide smoothly over alignment dowels
and must not be forced. Confirm that gasket material does not
overlap oil passages in crankcase and gear cover. See Picture 18.
7
Picture 16A Picture 16B
CAUTION
Picture 17