1. Fox DHX Coil Rebuild
Introduction:
This
is
a
guide
to
tearing
down
and
rebuilding
a
Fox
Racing
Shox
DHX
3/4/5
Coil
shock.
It
shows
the
user
how
to:
-‐ Dismantle
the
shock
-‐ Clean
internal
parts
-‐ Disassemble
the
Propedal
valve
and
spring
-‐ Disassemble
the
Rebound
assembly
(see
disclaimer)
-‐ Replace
internal
o-‐rings
-‐ Replace
main
shaft
seal
o-‐ring
-‐ Replace
oil
-‐ Reassembly
of
the
shock
unit
Note:
Disclaimer:
Fox
Racing
Shox
does
not
endorse
this
guide!
By
proceeding
with
this
guide,
the
instant
you
open
your
shock,
you
voluntarily
and
knowingly
forfeit
any
warranty
that
came
with
the
shock.
Rebound
Disassembly
requires
the
use
of
a
propane
torch
to
soften
loctite
used
to
secure
rebound
adjuster
eyelet
to
shock
shaft.
Soften
of
the
loctite
is
required
to
remove
the
eyelet.
BE
EXTREMELY
CAREFUL
WHEN
HEATING
THE
EYELET;
ONLY
HEAT
GENTLY
UNTIL
IT
IS
HOT
TO
TOUCH.
PROLONGED
HEATING
WILL
CAUSE
DAMAGE
TO
EYELET
AND
SHAFT
ASSEMBLY.
Do
not
proceed
with
these
procedures
if
you
are
not
mechanically
inclined!
If
you
have
a
tendency
to
round/strip
every
screw
you
touch,
put
the
tools
down
NOW!
Any
damage
you
cause
to
your
shock
due
to
your
own
mistakes
is
YOUR
FAULT.
Do
not
expect
any
sympathy
from
me,
or
any
sympathy
from
Fox
(or
warranty).
YOU
have
to
pay
to
have
the
unit
fixed.
This
guide
was
devised
with
care,
with
information
gained
from
a
number
of
sources.
This
procedure
works
if
carried
out
CAREFULLY
and
with
PATIENCE.
I
AM
NOT
RESPONSIBLE
FOR
ANY
DAMAGE
YOU
CAUSE
TO
YOUR
SHOCK,
BIKE,
PERSONA
OR
SURROUNDS,
USE
COMMON
SENSE
AND
TAKE
THE
FIRST
FEW
RIDES
EASY,
TO
ENSURE
YOU
HAVE
CORRECTLY
REPAIRED
THE
SHOCK.
WARNING!
READ
ALL
Instructions
twice
before
you
commence
with
the
rebuild,
and
ensure
you
understand
its
procedures
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2. Preliminaries
Tool
list:
-‐ Spanners
-‐ Long
Nose
Snap
ring
pliers
-‐ Small
block
of
wood
(to
create
makeshift
shaft
clamp)
-‐ Propane
torch
-‐ Loctite
thread
lock
-‐ Wooden
vice
-‐ Soft
jaw
vice
-‐ Long
nose
pliers
-‐ O-‐ring
/
Dental
picks
(for
removal
of
o-‐rings)
-‐ Clean
rags
-‐ Clean
work
bench
-‐ Oil
drip
Pan
-‐ Safety
glasses
-‐ Small
Breaker
Bar
-‐ 11mm
Drill
bit
Parts
list:
-‐ Replacement
o-‐rings,
the
best
way
to
get
these
is
to
take
the
removed
o-‐rings
to
a
local
0-‐ring
supplier
and
get
them
sized
up
properly
for
replacement
ones,
I
also
recommend
you
buy
a
good
amount
of
each,
it’s
always
good
to
have
spares
for
next
time,
label
them
and
put
them
in
a
compartment
container
-‐ Fork/shock
oil.
Ensure
you
use
a
high
quality,
fully
synthetic
oil.
I
use
10W
Castrol
Fully
synthetic
fork
fluid.
The
DHX
comes
stock
with
10W
Fox
Fluid
(rebadged
Silkolene
pro
RSF
10)
If
you
wish
to
use
a
different
weight
oil,
this
sight
has
a
lot
of
useful
info
on
shock
oil;
http://www.peterverdonedesigns.com/bikesuspension.htm-‐
Further
Information:
Here
is
a
list
of
websites
that
have
a
lot
of
useful
information
on
rear
shocks,
for
anyone
who
is
interested
in
learning
more
about
their
rear
shocks.
• Information
on
EVERYTHING
regarding
suspension,
explaining
different
types
of
damper
systems,
set
up
info
on
a
range
of
shocks
etc;
these
site’s
are
well
worth
reading
through!
:
http://www.krankin.co.nz/_sgt/m6m9_1.htm
http://users.actrix.co.nz/dougal.ellen/setup.html
http://users.actrix.co.nz/dougal.ellen/tuning.html
• Some
useful
info
on
how
to
mod
shim
stacks,
for
those
who
are
interested
in
modifying
their
shim:
stacks,
(undertake
this
at
your
own
risk!)
http://www.deycore.com/tuning_tips.htm
• Website
with
lots
of
info
regarding
things
like
oil
weights
etc:
http://www.peterverdonedesigns.com/bikesuspension.htm
Righto,
if
you
feel
confident,
and
have
read
this
guide
at
least
twice
(yes
that
was
an
instruction!),
clean
your
work
area,
gather
your
tools,
and
lets
begin!
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3. STEP
1:
Removing
shock
1. Firstly,
you
will
need
to
remove
shock
from
your
bike;
it
will
be
different
on
every
bike,
so
if
you
don’t
know
how
to
remove
your
shock,
STOP
NOW!
2. After
you
have
removed
the
shock
from
the
bike,
place
on
your
work
bench,
and
give
it
a
good
wipe
over
with
a
clean
cloth,
to
remove
dust
and
dirt
3. Next
remove
you
spring,
and
in
my
case,
my
shock
boot
4. Back
off
all
adjustments
(Least
Propedal,
Bottom
Out
and
Rebound)
5. DEFLATE
THE
BOOST
VALVE!
6. Give
the
shock
body
a
good
clean,
you
don’t
need
any
dirt
or
debris’s
getting
inside
the
shock
7. Clamp
the
shock
body
in
a
wooden
vice
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4. STEP
2:
Removing
Bottom
Out
Adjuster
8. Loosen
the
two
grub
screws
on
the
bottom
out
adjuster
with
a
hex
key
9. Remove
the
adjuster,
and
set
it
aside
10. Using
either
a
spanner
or
wrench,
loosen
the
grey
cap
11. After
the
threads
have
been
disengaged,
pull
the
assembly
out,
and
set
it
aside
12. You
can
now
see
the
IFP
(Internal
Floating
Piston)
and
the
bleed
screw
in
the
middle
13. Use
a
measuring
device
and
measure
the
depth
of
the
IFP,
The
depth
will
be
different
for
different
stroke
lengths
and
eye
to
eye
measurements
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5. STEP
3:
Removing
the
IFP
14. Depress
the
shaft
all
the
way
down
15. Remove
the
bleed
screw
from
the
centre
of
the
IFP
with
a
hex
key
16. Pull
the
bleed
screw
out,
and
set
it
aside
in
a
safe
place
17. Using
long
needle
nosed
pliers,
pull
the
IFP
out
of
the
Piggyback
Chamber
18. Remove
the
IFP
19. Place
the
IFP
aside,
and
pull
the
shaft
out
to
full
extension
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6. STEP
4:
Removing
the
Shaft
assembly
20. Wrap
an
old
tube
around
the
shaft,
this
will
prevent
damage
to
the
shaft
should
you
slip
with
the
spanner
21. Using
a
spanner
or
wrench,
undo
the
shaft
cap,
it
may
be
tight,
keep
applying
even
pressure
and
it
will
undo
22. After
its
loosened,
use
your
hand
to
unthread
the
shaft
23. Pull
the
shaft
and
piston
assembly
out
of
the
shock
body
24. Set
the
shaft
assembly
aside
25. Drain
the
oil
from
the
Piggyback
and
main
chamber
into
an
oil
pan,
wipe
the
body
with
a
clean
cloth
and
set
the
body
aside
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7. STEP
5:
Removing
Piston
and
Seal
Housing
Assembly
26. Clamp
the
shaft
eyelet
reducers
in
a
soft
jaw
vice,
or
use
blocks
of
wood
as
shown
in
the
first
picture,
this
will
prevent
damage
to
the
reducers
27. Use
a
small
spanner
and
undo
the
black
piston
bolt
28. Remove
the
piston
and
shim
assembly,
be
careful
not
to
lose
or
muck
up
the
shim
stack
29. Lift
off
the
black
seal
housing,
being
careful
not
to
knock
the
rebound
needle
in
the
centre
of
the
shaft
30. Place
the
seal
housing
on
your
work
bench,
be
careful
not
to
scratch
the
orange
bushing
31. You
can
now
access
the
yellow
dust
seal
and
black
main
shaft
o-‐ring
between
the
yellow
dust
wiper
and
orange
bushing
32. If
you
shock
has
had
sufficient
use
there
will
probably
be
dirt
and
crud
in
the
yellow
dust
seal,
wipe
it
clean
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8. STEP
6:
Removing
Shaft
O-‐ring,
IFP
O-‐ring
and
Housing
O-‐Ring
33. Using
a
pin
or
dental
pick,
stab
the
black
o-‐ring
and
pry
it
out,
being
careful
not
to
scratch
the
yellow
dust
seal
or
orange
bushing
34. Label
the
o-‐ring
so
you
know
which
one
it
is
and
set
it
aside
for
now
35. Using
you
pick,
remove
the
housing
o-‐ring
36. Label
the
housing
o-‐ring,
and
put
it
aside
37. Using
your
pick,
remove
the
IFP
o-‐ring
38. Label
the
IFP
o-‐ring
and
set
it
aside
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9. STEP
7:
Removing
Bottom
Out
assembly
o-‐rings
and
cleaning
shock
internals
39. Using
your
pick,
remove
the
bottom
out
plunger
o-‐ring,
label
and
set
aside
the
o-‐ring
40. Using
your
pick,
remove
the
Bottom
out
housing
o-‐ring,
label
and
set
aside
the
o-‐ring
41. The
Bottom
out
assembly
with
its
o-‐rings
42. Using
a
clean
cloth,
wipe
out
the
main
shaft
chamber
43. Using
a
clean
cloth,
wipe
out
the
piggyback
chamber
44. You
have
now
disassembled
you
shock.
Take
the
o-‐rings
to
a
local
supplier
and
have
them
sized
up
and
replaced,
I
recommend
getting
a
quantity
of
each,
labelling
them
and
putting
them
in
a
container
for
next
time,
it’s
always
good
to
have
a
supply
of
them
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10. STEP
8:
Replacing
main
shaft
o-‐ring
and
shaft
housing
o-‐ring
45. Take
your
new
main
shaft
o-‐ring,
apply
a
few
drops
of
suspension
oil
to
it
and
pinch
as
shown
46. Insert
the
pinched
o-‐ring
into
shaft
housing
as
shown
47. Place
your
pinkie
in
opposite
end
as
shown
48. Using
you
other
pinkie,
squash
the
o-‐ring
into
the
housing
and
use
your
fingers
to
set
the
o-‐ring
in
its
housing,
this
can
be
tricky,
take
your
time
and
it
will
go
in
49. Take
you
new
shaft
housing
seal,
and
place
a
few
drops
of
suspension
oil
onto
it
50. Insert
it
back
onto
housing
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11. Step
9:
Rebound
Disassembly/Reassembly
51. Shaft
with
piston
removed.
Drill
a
11mm
hole
into
small
block
of
hardwood,
then
cut
in
half
52. Insert
shaft
into
clamps
as
shown,
tighten
clamps
in
vice
53. Using
propane
torch,
GENTLY
heat
eyelet/shaft
junction
until
hot
to
touch
54. Insert
breaker
bar
into
eyelet,
then
unscrew
eyelet
from
shaft,
if
shaft
spins,
ensure
clamp
is
tight
and
that
eyelet
is
hot
55. When
eyelet
unscrews
from
shaft
threads,
rebound
needle
and
the
small
o-‐ring
will
be
exposed
56. Using
a
brush,
ensure
all
loctite
is
removed
from
the
shaft
threads
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12.
57. Press
rebound
needle
out
of
shaft,
replace
small
o-‐ring
at
threaded
end
of
shaft
58. The
rebound
system
has
been
fully
disassembled
59. Clean
all
remaining
loctite
from
eyelet
threads
with
a
brush
60. Unscrew
rebound
adjust
from
eyelet,
being
careful
not
to
loose
the
detent
ball
or
spring
61. Clean
both
adjuster
and
insides
of
the
eyelet,
regrease
both,
then
reinsert
the
adjuster
in
eyelet
62. Clean
and
lightly
grease
rebound
needle,
then
reinsert
into
the
shaft,
ensure
that
the
small
o-‐ring
at
threaded
end
has
properly
engaged
over
the
needle
and
that
it
is
sitting
flush
in
its
small
shaft
recess
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13.
63. Reinsert
the
shaft
into
the
clamps,
place
a
small
amount
of
loctite
on
threads,
ensure
loctite
does
not
spill
into
rebound
needle
or
on
shaft
surface
64. Reinstall
the
eyelet
onto
the
shaft,
hand
tighten,
the
ensure
clamps
are
tight
65. Using
breaker
bar,
retighten
the
eyelet,
the
clamps
will
needed
to
be
significantly
tight
to
ensure
that
eyelet
tightens
properly
66. Remove
shaft
from
the
clamps
and
clamp
the
eyelets
into
the
vice.
Using
a
small
Allen
key,
gently
push
down
on
the
rebound
needle
so
that
it
engages
the
adjuster
67. Using
a
syringe,
inject
suspension
oil
down
into
the
rebound
assembly
to
purge
air,
cover
the
rebound
hole
if
needed.
The
rebound
assembly
is
now
rebuilt.
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14. Step
10:
Propedal
Disassembly/
Reassembly
(Many
thanks
to
Enemy1
for
Pics
and
instructions)
68. To
Access
Propedal
Spring
and
plate
o-‐ring,
with
shock
clamped
upright
in
vice,
remove
the
snap
ring
using
long
nose
circlip
pliers
69. Replace
o-‐ring,
then
reinstall
spring
back
in
reservoir,
along
with
Propedal
base
plate,
then
reinstall
circlip,
insuring
the
it
is
properly
seated
in
the
recess.
(Second
Picture
shows
reservoir
with
Propedal
assembly
removed
70. Unscrew
black
bottom
out
plunger
from
grey
housing
71. Remove
and
replace
o-‐ring,
then
reinstall
black
bottom
out
plunger
in
grey
housing
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15. STEP
11:
Replacing
IFP
and
Bottom
Out
assembly
o-‐rings,
reassembling
shaft
assembly
72. Place
a
few
drops
of
suspension
fluid
on
a
new
IFP
o-‐ring,
and
place
it
back
on
the
IFP
(In
picture,
new
o-‐
ring
in
place
on
IFP,
old
one
next
to
IFP)
73. Place
a
few
drops
of
suspension
fluid
on
new
bottom
out
housing
and
adjuster
o-‐rings,
then
place
them
back
on
the
assembly
(the
position
of
the
old
o-‐rings
on
the
table
is
respective
of
where
they
go
on
the
BO
assembly)
74. Wipe
some
suspension
fluid
on
shaft,
and
replace
rubber
bottom
out
bumper
75. Reinsert
the
shaft
seal
housing
back
onto
the
shaft,
be
careful
to
put
it
on
straight,
take
your
time,
DO
NOT
FORCE
IT,
otherwise
damage
to
the
shaft
or
bushing
may
result
76. Replace
the
piston/shim
assembly,
and
retighten.
Just
snug
it
tight,
if
you
over
tighten
it
too
much,
you
may
crush
the
shims
and
prevent
them
flexing
77. After
you
have
retightened
the
piston,
pull
the
shaft
housing
all
the
way
up.
Coat
Piston
and
shim
stack
in
oil,
as
to
minimize
air
in
shim,
piston
assembly.
You
have
now
successfully
rebuild
the
shaft
assembly
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16. STEP
12:
Refilling
oil
and
reinstalling
shaft
assembly
78. Refill
the
main
chamber
with
oil
79. Let
it
filter
into
piggyback
chamber
and
keep
filling
until
piggyback
chamber
is
almost
overflowing
80. Place
the
IFP
into
the
chamber,
press
it
so
it
just
sits
on
the
top
of
the
threads
(ensure
bleed
screw
is
in)
81. Fill
main
chamber
with
suspension
oil
until
it
is
almost
overflowing
82. While
holding
IFP
in
place,
reinsert
the
piston
into
the
chamber
and
thread
the
seal
housing
on,
hand
tighten
it
at
this
stage
83. Remove
IFP
bleed
screw
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17. STEP
13:
Reinserting
IFP
and
reinstalling
Bottom
Out
assembly
84. Depress
IFP
past
threads,
ensure
bleed
screw
is
removed,
and
wear
safety
glasses,
as
oil
will
squirt
through
bleed
hole
85. Using
you
measuring
tool,
push
IFP
to
its
correct
depth.
If
you
did
not
record
your
IFP
depth,
use
the
depth
chart
at
the
end
of
this
document.
Tap
body
to
displace
any
trapped
air
as
your
pushing
the
IFP
in,
this
will
ensure
a
good
bleed
86. Reinstall
bleed
screw,
drain
and
wipe
excess
oil
from
IFP
chamber
87. Using
spanner
or
wrenches,
retighten
the
shaft
housing.
Its
recommended
that
you
use
the
old
tube
to
protect
the
shaft
88. Reinsert
the
bottom
out
assembly
89. Using
a
spanner
or
wrench,
tighten
the
grey
cap
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18. STEP
14:
Final
Reassembly
90. Reinstall
the
Bottom
Out
adjuster
cap
91. Tighten
the
2
grub
screws
92. Reinflate
the
boost
valve
to
a
minimum
of
125PSI
93. Clean
the
shock
over
with
Isopropyl
Alcohol
or
a
wet
cloth
94. Reinstall
spring,
any
reducers
and
valve
cap
(and
in
my
case,
my
shock
boot)
95. Reinstall
the
shock
back
onto
your
bike
96.
Do
the
bounce
test
on
your
bike
to
lube
internal
parts,
then
set
adjustments
to
you
settings,
bounce
check
again
to
make
sure
everything
is
working
correctly
97. Success
=
BEER!
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19. IFP
Depth
Chart:
EYE
to
EYE
–
Stroke
Metric;
190mm,
50mm
=
32mm
200mm,
50mm
=
32mm
200mm,
57mm
=
33mm
215mm,
64mm
=
34mm
222mm,
64mm
=
34mm
241mm,
76mm
=
38mm
Imperial;
7.500,
2.00
=
1.25
7.875,
2.00
=
1.25
7.875,
2.25
=
1.30
8.500,
2.50
=
1.35
8.750,
2.50
=
1.35
9.500,
3.00
=
1.48
Thanks
to
EmanResu
on
MTBR
for
finding
the
IFP
chart
Thanks
to
Enemy1
for
Propedal
instructions
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20. Acknowledgements
Big
thanks
to
the
people
who
contributed
their
valuable
knowledge
to
help
me
compile
this
guide,
id
name
you
individually,
but
you
know
who
you
are!
Info
obtained
from
people
on:
-‐ MTBR
-‐ Pinkbike
-‐ ROTORBURN
AUSTRALIA
(formally
FARKIN)
-‐ Ride
Monkey
th
Compiled
By
me,
Nick_M2R
on
18
May
2009
th
Updated:
28
January
2010
While
I
have
proof
read
this
guide
carefully,
but
I’m
only
human.
If
you
have
notice
any
mistakes
or
have
any
improvements,
PM
me
on
MTBR
and
ill
include
them
in
future
releases.
Enjoy
Guys
and
Girls!
Version:
4
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