Troy-Bilt 424 User Manual

Make certain chipper 
blades are reassem-
bled with the sharp 
edge outward (toward 
the chipper chute). 
Torque hardware to 
between 20 ft.-lbs and 
25 ft.-lbs.

2.  Pivot the shredder screen upward as instructed under 

the heading Cleaning the Reduction Chamber.

3.  a. Remove the chipper chute support brace from the 

frame by removing the two hex bolts and saddle 
washers which secure it. See Figure 9.

  b. Remove the chipper chute by removing three hex 

nuts and washers which secure it to the impeller 
housing. See Figure 9.

  •  Rotate the impeller by hand until one of the two 

chipper blades is visible through the impeller 
housing opening.

  c.  Remove the blade by removing the internal hex 

screws, lock washers and hex nuts which secure it 
to the impeller. Retain the hardware.

NOTE: Use a 3/16” hex key (Allen) wrench on the outside 
of the blade and a 1/2” box (or socket) wrench on the 
inside of the impeller. Hold the Allen wrench stationary 
and rotate the box (or socket) wrench to loosen the nut.

4.  Install a replacement blade (Part No. 742-0544) with 

the hardware removed earlier or sharpen.

IMPORTANT: When sharpening the blade, protect hands 
by using gloves. Follow the original angle of grind and 
make sure to remove an equal amount from each blade.
5.  To replace the other blade, rotate the impeller to 

expose the second blade and repeat the steps above.

NOTE:  Make certain blades are reassembled with the 
sharp edge outward (toward the chipper chute). Torque 
hardware to between 20 ft.-lbs and 25 ft.-lbs.

1.  Stop engine,disconnect spark plug, and make certain 

that all moving parts have come to a complete stop.

2.  Remove the two flange nuts (and hex bolts) which 

secure the hopper support bracket to the impeller 
housing. Retain the hardware. See Figure 10.

3.  Pivot the shredder screen upward as instructed under 

the heading 

Cleaning the Reduction Chamber.

4.  a. Remove six flange nuts which secure hopper inlet 

guide to impeller housing. See Figure 11.

  •  Carefully separate the hopper assembly from the 

impeller housing and set it aside.

  •  Insert a piece of wood into the chute deflector 

opening to stabilize the impeller and prevent it from 
rotating when removing the shredder blade.

  b. Remove the two internal hex screws, hex lock nuts, 

and lock washers which secure the shredder blade 
to the impeller. See Figure 11.

NOTE: Use a 3/16” hex key (Allen) wrench on the 
outside of the shredder blade and a 1/2” box (or socket) 
wrench on the inside of the shredder blade. Hold the 
Allen wrench stationary and rotate the box (or socket) 
wrench to loosen the nut.
 
  c.  Remove the hex bolt, lock washer, and flat washer 

to completely free shredder blade. See Figure 11.

IMPORTANT: If sharpening the blade for reuse, follow 
the original angle of grind as a guide. Make certain each 
cutting edge receives an equal amount of grinding to 
prevent an unbalanced blade. Remove metal from the 
heavy side until it is balanced evenly.

IMPORTANT: When reassembling the blade, tighten 
center bolt to between 45 ft.-lbs and 60 ft.-lbs and the 
two out bolts to between 20 ft.-lbs and 25 ft.-lbs.

1.  Clean the equipment thoroughly.
2.  Wipe equipment with an oiled rag to prevent rust.
3.  Refer to engine manual for correct engine storage 

instructions

4.  Store unit in a clean, dry area. Do not store next to 

corrosive materials such as fertilizer.

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When reassembling the 
shredder blade, tighten 
center bolt to between 
45 ft.-lbs and 60 ft.-lbs 
and the two out bolts to 
between 20 ft.-lbs and 
25 ft.-lbs.