DR Power Tow-Behind 13.74 Pro-XL (August 2010 - August 2014) - Manual (Page 26)

26 DR ® LEAF and LAWN VACUUM
Removing and Replacing the Chipper Blade
Tools Needed:
 1/2" Wrench

3/16" Allen Wrench

Awl or pointed tool
NOTE: Be careful not to drop any parts or hardware down into the Impeller
Housing as you perform the following steps.
1. Remove the four Locknuts from the Hopper with a 1/2" Wrench and remove
the Hopper ( Figure 45 ).
2. Remove the Inlet Duct from the Impeller Housing by unscrewing the Hand
Knob and sliding the Duct from the Housing Lip (Figure 46).
3. If the Collector is empty you can tip it back to allow better access to the rear
of the Impeller Housing.
4. Carefully rotate the flywheel with a stick until the Knife is at the Hopper
opening (Figure 47).
NOTE: You may need to clean out the hexes of the Knife Screws with an Awl to
enable you to get the Allen Wrench fully into the Screw hexes. Carefully observe the
orientation of the Chipper Blade edge and mounting holes when removing the Blade.
5. Insert the 1/2" Wrench into the Impeller Inlet Hole to access the Locknuts
on the back side of the Knife.
6. Insert the 3/16" Allen Wrench into the a Knife Screw and hold the Screw as
you turn the Wrench on the back side.
7. Clean the Knife mounting area of the Flywheel so the new Knife will mount
flush to the Flywheel.
8. Position the new Knife with the cutting edge facing out and towards the
opening in the Flywheel. Secure with the new hardware that came with your
Knife Kit using the 1/2" Wrench and 3/16" Allen Wrench. Tighten the center
Screw and Locknut, then tighten the outer Screw and Locknut, and finally
tighten the inner Screw and Locknut. Double-check that all three Locknuts
on the Allen Screws are tight.
9. Replace the Hopper and Inlet Duct.
Knife
Cutting
Edge
Figure 47
Screws with
Locknuts
Impeller
Opening
 Before performing any maintenance, repairs or inspection, you must first shut off the mower and leaf and lawn vacuum
engines, wait five minutes for all parts to stop and cool and disconnect the spark plug wire of the leaf and lawn vacuum.

Do not attempt to re-sharpen the chipper blade. This will unbalance the impeller and may damage the engine and Impeller.
Always replace a dull or damaged chipper blade with a new blade.
 Inspect the elbow for wear if the impeller is worn.
Hopper
Figure 45
Four
Locknuts
Impeller
Housing
Inlet
Duct
Figure 46
Hand Knob