S&S Cycle Breather Valve for 1999-2006 Big Twin Engines User Manual

Page 2

INTRODUCTION
The S&S

Breather Valve assembly is designed to eliminate

oil carry over in 1999-2006 Harley Davidson

Twin-Cam 88

engines. It fits "A" (non-counterbalanced) engines.

The Crankcase Breather Valve for 1999-2006 engines was
designed and developed for use with stock Harley-
Davidson

oil pumps and tappets, and may not be

compatible with some aftermarket components.

It is necessary to remove and re-install the camshaft
assembly to install the Breather Valve Assembly. This
installation requires specialized tools and knowledge, and
should be performed by an experienced mechanic with
access to a Harley Davidson

service manual and all

required tools.

Part 31-2070 — Fits 1999-2002 Twin Cam 88

"A" engines.

Part 31-2071 — Fits 2003-2006 Twin Cam 88

"A" engines.

KIT CONTENTS
One pre-assembled Breather Valve Assembly and
wave spring.

A. Installation instructions

1. Disconnect negative terminal of battery to

eliminate potential sparks and inadvertent
engagement of starter while working on
motorcycle.

Remove cam cover, camshaft assemblies, cam
support plate and oil pump per appropriate
Harley-Davidson

service manual instructions.

3. Breather Valve Assembly installs by hand into the

crankcase pinion bearing bore. See Picture 1.

NOTE: Some OEM engine cases have a sharp edge at the
top of the bearing bore. Item #4 O-ring must compress
past the top edge of the pinion bearing bore during
installation. If the top edge of the pinion bearing bore is
sharp enough to damage the O-ring, carefully break the
edge with a suitable de-burring tool to prevent damage
to the O-ring when the Breather Valve Assembly is
installed. Do not allow any material removed during the
de-burring operation to remain in the engine.

4. Lubricate item #4 O-ring, and item #2 seal, with

assembly lube before installing.

NOTE: The Breather Valve Assembly may be installed
rotated to any position.

5. Position Breather Valve Assembly on pinion

shaft, with item #4 O-ring at top edge of
crankcase bearing bore. Carefully push the
Breather Valve Assembly by hand into the bore
until the back of the Breather Valve housing
seats on the pinion bearing outer race. The O-
ring may be rocked slightly to aid starting it into
the bore. Use care not to damage the O-ring, or
unseat it from its groove when pressing it into
place.

6. Position item #1 wave spring in counterbore of

Breather Valve Assembly. Wave spring can be
installed with either side up. Apply a sufficient
amount of wheel bearing grease to hold wave
spring in position during oil pump and cam plate
installation. Breather Valve Assembly is held in
place by the wave spring, which is compressed
between the Breather Valve Assembly and the oil
pump body. See Picture 2.

Picture 1

Picture 2