How To Install A Lawn Mower Blade & Clear Your Transmission of Debris Main Image

If you're sharpening your blade or just installing a new replacement, make sure that you attach your blade so that it's facing the right direction otherwise your quality of cut will decrease. Many blades have indicators like "top", "bottom", and "deck" (or similar words) to indicate how you should re-mount your blade on the mower. Also, regular transmission maintenance can help keep your transmission in better health. Debris, string or other foreign objects wrapped around a transmission shaft can lead to locked-up bearings, which might cause leakage or other damage.

Here's a quick recap of the video:

How To Install A Lawn Mower Blade on a Rotary Mower

  • If you're using a Honda mower with the dual blades, make sure you assemble the blades in the correct order prior to installation. One way to tell how they fit together is by looking at the orientation of the "clean" spots on the blade (where the grass and debris aren't) and where the bolts have been previously attached.
  • Traditionally, lawn mower blades will have a "flat" side that will face the grass side, or bottom of the mower.
  • Find and set the "cutting edge" face of the blade. Then, set the angle of your grinder to match the pitch of the blade angle.
  • After you've set the blades on the mower, hand tighten the nuts onto the blade bolts. Always hand tighten your bolts when you're starting them onto the threads. Never use a machine or impact tool or you may damage the threads of the bolt which could lead to a dangerous situation. If the nuts are not securely fastened (either due to over-tightening, stripped threads or under-tightening), your blade could potentially cause damage to you, your lawn and your mower.
  • Before using any tool, make sure you that equip yourself with a thick rag or welding-style glove. Carefully hold onto the non-sharpened edge of the blade and tighten the bolts using an impact wrench or other tool.

Cleaning Your Lawn Mower Transmission

  • Remove any debris, string or any other foreign objects from around the transmission and transmission axle. In this video, there were strings wrapped around the axle shaft. If those strings were to wrap around and penetrate the bearing, it could cause the bearing to dry out the bearing, lock it up, or cause a wet transmission to leak and become damaged.
  • Look for sticks, debris, grass or other foreign objects/obstructions inside the mower and belt housing as these items can decrease your transmission and belt life.