How to Fix a Weed Trimmer

The gasoline-powered weed trimmer, commonly called a string trimmer, is a very reliable piece of landscaping equipment. These little two-cycle wonders are extremely durable and trouble-free, requiring very few repairs. Of those few repairs, the most common is replacement of the clutch. Fixing this problem doesn't require any unusual or special tools and can be handled by even a novice repairperson.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Torx driver
• Phillips screwdriver
• Allen wrench set
• Internal snap ring pliers
• External snap ring pliers
• 9/16 inch socket
• Large arc-joint pliers

1. Remove the screws holding the clutch housing to the engine. These will be either a small Torx or Phillips head screw. Most machine will have five screws.

2. Bend the gas tank support bracket down enough to provide the necessary clearance to remove the clutch hosing from the engine. Also pry the plastic housing tab away from the top screw boss.

3. Remove the shaft and clutch housing assembly. The throttle cable and engine wiring harness will not allow these to be completely detached from the engine.

4. 
    

   Using a 9/16 inch socket, preferably driven by an air impact wrench, remove the clutch show retaining bolts. If an impact wrench is not available, a 1/2 inch drive ratchet will do, but the clutch must be held with large pliers while the bolts are removed.

5. Remove the clutch from the engine (if it hasn't fallen off already) and discard.
   Do not lose the small washers that go between the clutch shoes and the mounting boss on the engine.

6. 
    

   Assemble the new clutch shoes and spring. This is easier if the spring is installed before the shoes are aligned.

7. Place the small flat washers on the clutch mounting bosses on the engine block and set the clutch assembly in place. Install the retaining bolts with the wafer washer through the holes in the clutch shoes, the flat washers and the mounting boss. Tighten these bolts securely, but not so tight that the clutch shoes bind. The shoes must snap shut when they are pried apart and released.

8. Examine the clutch drum for wear. If it's not seriously worn, assemble the clutch housing back to the engine and replace the screws. If the drum is thin, replacement will be necessary.

Replacement of the clutch drum

9. Remove the three Allen head screws holding the clutch housing to the trimmer shaft, and slide the clutch housing off the shaft.

10. Pull the bottom section of the shaft clamp out of the housing. Next, push the upper section into the space where the bottom half was and pull it out of the housing. Finally, remove the rubber insert from the housing.

11. Using small internal snap ring pliers, remove the lock ring from the bearing deep inside the housing.

12. Pull the clutch drum from the housing. It may be necessary to use some effort to pull the drum out of the bearing.

13. Install the new drum into the bearing and replace the small snap ring on the inside of the housing.

14. Install the rubber sleeve back in the clutch housing, then install the top half of the shaft clamp. As soon as that piece is in place, install the bottom half of the clamp. Slide the entire assembly back onto the shaft and replace and tighten the Allen head screws.

15. Bolt the clutch housing to the engine and the job is complete.

Who Can Help Sponsored

• Earn your degree from industry experts at University of Phoenix. Take the next step in your career.