Caution warning – S&S Cycle 5-Speed Trasmission Case for 1986-99 Big Twin and Custom Applications User Manual

Page 2

INTRODUCTION
S&S

transmission cases are made from virgin 356T6 aluminum

alloy and machined with state-of-the-art CNC equipment. S&S
Transmission Case 56-1050 fits 1986-1999 Harley-Davidson

Softail

models (1986-1988 models require Starter Adapter Kit 56-

1046.) and custom applications.

S&S 5-Speed Transmission Case includes shift lever adjustment
screw, shifter shaft guide, and all studs and dowel pins required
for assembly. S&S transmission case accepts stock and aftermarket
5-speed style trap doors, gears, shafts, bearings, and other parts
designed for 1986-1999 Softail

transmission.

NOTES
●

Starter Adapter Kit 56-1046 required for 1986-1988 models
can be purchased separately through S&S dealers or direct.

●

When building a transmission, S&S recommends using the
1987-up style trap door and end cover with “ball and ramp
clutch actuator. Strength of lever-type actuator is marginal
for heavy duty clutch springs sometimes required in high-
performance applications.

Following options are available for S&S Transmission Case
Part 56-1050:

●

Bearing and Seal Kit 56-1050B.

●

Trap Door Assembly 56-1027 (Includes door bearings and
miscellaneous hardware.)

●

Starter Adapter Kit for 1986-’88 style starter, 56-1046.

INSTALLATION
If required, 1986-’88 Starter Adapter Kit 56-1046 should be
installed before assembling transmission.

To install Starter Adapter Kit:
1.

Carefully support starter area of transmission case on table
of hydraulic press. Apply thin film of Loctite

#609 (green)

to outer edge of starter adapter spacer 56-1066 and
corresponding area of transmission case. Press spacer into
case until flush with starter mounting surface.

Remove dowel pin 50-8171 (Item 8, Figure 2)

Apply thin film of oil to outside of dowel pin 50-8029,
dowel pin 50-8172, and roll pin 50-8174 (Items 2, 3, and 4,
Figure 1) and press into transmission case until flush with
inner primary mounting surface.

Install starter seal 56-1065 in adapter spacer. Seal must be
flush with outer surface of spacer.

NOTE: Install seal with spring side toward primary cover. Confirm
fit of starter drive housing and inner primary cover on
transmission case.

ASSEMBLY
Assembly of transmission using S&S case for Softail

models and

related parts is identical to assembly of transmission using stock
components. Refer to following notes and Harley-Davidson

Service Manual.

NOTES
●

Several differences exist between Harley-Davidson

5-speed

transmissions of certain year groups. Most common
differences are between shifter cams, main drive gears,
sprockets, spacers, and seals. Correct parts must be used for
each year group and transmission must be assembled
according to Harley-Davidson

Service Manual for

appropriate model year. Shift lever adjuster screw 56-1002
(See Figure 2) will require adjustment after transmission
assembly/installation and before operation of motorcycle.
See Harley-Davidson

Service Manual for further

information. After adjustment, secure screw with hex-head
nut 50-5044. See Figure 2.

●

Inspect all parts before installation in case. Shifter forks are
especially critical for proper operation of transmission.
Confirm shifting through all five gears before installing
transmission. Shifting will be stiff with transmission out of
motorcycle, and it will be necessary to rotate transmission
sprocket back and forth to engage some gears.

●

Early-style (pre-1992) transmission sprockets use a
sockethead screw as sprocket nut retainer. S&S recommends
modifying early-style sprocket to accept sprocket nut
lockplate H-D

#40251-92. To modify early sprocket for

lockplate, install sprocket and torque sprocket nut to 110-
120 ft-lbs. Place lockplate over nut and against sprocket. Use
one of four holes in lockplate as guide and drill and tap
sprocket for

⁄

-20 x

⁄

sockethead screw H-D

#3594A. Clean

threads of screw with Loctite

Primer or equivalent, apply

Loctite

#242 (blue) to threads, and install screw to secure

lockplate. Tighten to 50-60 in-lbs. as explained in Harley-
Davidson

Service Manual. Remove metal chips before

continuing installation.

Parts must be adequately supported when using hydraulic
press. This is especially true when installing bearings in trap
door. Failure to support parts correctly may result in damage
not covered under warranty.

●

Proper assembly of transmission with correct parts in good
condition is critical for safe operation of motorcycle.
Transmission malfunction can cause rear wheel to lock and
tire to skid. In some instances of transmission malfunction,
disengagement of clutch will not free wheel.

●

Never reuse transmission retaining rings. Damaged
retaining ring may permit engagement of two gears at
once. This can result in seized transmission and loss of
control of motorcycle with severe personal injury to
operator and others.

All reference to Harley-Davidson

part numbers is for

identification purposes only. We in no way implying that any of
S&S

Cycle’s products are original equipment parts or that they

are equivalent to the corresponding Harley-Davidson

part

number shown.

CAUTION

WARNING