Use and Care Manual
DUAL LAWN MOWER
BLADES
AC04024
For use with RYOBI RY401015/RY401020
21 in. 40V Lawn Mower ONLY
998000538
3-8-21 (REV:01)
WARNING!
To reduce the risk of injury, user must
read and understand the operator’s
manual for their lawn mower and this
instruction sheet. Always wear eye
protection with side shields marked
to comply with ANSI Z87.1. Ensure
compatibility and fit before using this
accessory. Do not use this accessory
if a part is damaged or missing. If you
are not comfortable performing any
of the functions described in these
instructions, take your unit to a quali-
fied service center.
WARNING:
Always protect hands by wearing
heavy gloves and/or wrapping the
cutting edges of the blade with rags
and other material when performing
blade maintenance. Contact with the
blade could result in serious personal
injury.
REPLACING THE CUTTING
BLADE
See Figures 1 - 2.
Stop the motor and remove the start
key. Allow the blades to come to a
complete stop.
Remove the battery packs from the
battery port.
Turn the mower on its side.
Wedge a block of wood between the
blades and mower deck to prevent
the blades from turning.
Loosen the blade nut by turning it
counterclockwise (as viewed from
bottom of mower) using a 15 mm
wrench or socket (not provided).
Remove the blade nut, spacer, blade
insulator, and blades. Do not remove
the hub or the adaptor.
Inspect the blades and replace one
or both as needed.
WARNING:
If the hub and/or the adaptor have
been removed, replace them before
placing blades on the shaft. Failure
to do so could cause the blades to
detach or become unbalanced since
blades will not tighten properly, which
can result in serious personal injury.
Place the new blade on the shaft
against the blade posts on the hub.
Ensure blade is properly seated with
shaft going through center blade hole
and the two blade posts on the hub
inserted into their respective holes
on the blade. Make sure it is installed
with the curved ends pointing up to-
ward the mower deck and not down
toward the ground. When seated
properly, the blade should be flat.
Replace the blade insulator and
spacer, then thread the blade nut on
the shaft and finger tighten.
NOTE: Make certain all parts are
replaced in the exact order in which
they were removed.
Torque the blade nut down clockwise
using a torque wrench (not provided)
to ensure the bolt is properly tight-
ened. The recommended torque for
the blade nut is 325 – 400 in.lbs.
Repeat with the second blade, if
needed.
WARNING:
Ensure blades are properly seated
and the blade nut is tightened to the
torque specifications above. Failure
to properly attach the blades could
cause them to come loose and result
in possible serious personal injury.
TECHTRONIC INDUSTRIES POWER EQUIPMENT
P.O. Box 1288, Anderson, SC 29622 USA
1-800-525-2579 • www.ryobitools.com
Fig. 1
A
BC
Fig. 2
A - Adaptor (adaptateur, adaptador)
B - Hub (arbre, eje)
C - Blade post (half circle) [tige pour lame (demi-
cercle), puerto de la hoja (semicircular)]
D - Blade post (round) [tiges pour lame (ronde),
montantes de cuchilla (Redondo)]
E - Upper blade (lame supérieure, hoja superior)
F - Blade hole (half circle) [trou pour lame (demi-
cercle), orificio de la hoja (semicircular)]
G - Blade hole (round) [trou pour lame (ronde),
orificio de la hoja (redondo)]
H - Lower blade (lame inférieur, hoja inferior)
I - Blade hole (half circle) [trou pour lame (demi-
cercle), orificio de la hoja (semicircular)]
J - Blade hole (round) [trou pour lame (ronde),
orificio de la hoja (redondo)]
K - Blade insulator (isolant de lame, aislante de hoja)
L - Spacer (entretoise, separador)
M - Blade nut (écrou de lame, tuerca de la hoja)
N - Shaft (arbre, eje)
N
C
G
J
E
H
D
B
A
L
M
K
F
I
A - Blade (lame, hoja)
B - Wrench (clé, llave)
C - Block of wood (pièce de bois, bloque de madera)