Trimmer with terrible vibrations

   / Trimmer with terrible vibrations #1  


Feb 7, 2020
Northwest Arkansas
Farmall H and Kubota MX6000
I have a nice string trimmer - Husqvarna 525L professional - that I bought new a couple of years ago. It is a great tool, but sometimes it gets into a mode where it vibrates horribly and just about shakes my hands off. this happens for many minutes at a time, then self-corrects, then comes back later. Overall it does this about half the time, and the intensity of the vibration is not always the same. The vibration is not quite as bad as when one string breaks off, but at times almost that bad. Sometimes bumping it for more string helps, but usually not. I have stopped and taken the string spool out and sometimes even rewind it - no help. I've wondered about the engine causing this, but it seems to be running fine, whether the vibrations are happening or not. Any ideas what is going on with this?
   / Trimmer with terrible vibrations #3  
When vibration occurs is there any grass wrapped on the string head? I have had this happen on my Echo where a clump of grass gets caught and wraps in the trimmer head. Sometimes self cleans and sometimes require pocket knife to cut grass out of the head.
   / Trimmer with terrible vibrations
  • Thread Starter
Sometimes grass does wrap around it, but I always clear that. The string head on this machine is very smooth, so when grass does wrap around it, the grass isn't moving with the head - it binds up and rubs on the rotating head but doesn't affect the vibration either way.
   / Trimmer with terrible vibrations #6  
Shaft collar might be broken or moving in and out of position?
I’ve had to replace these types of parts many times in my overly abused Stihl trimmer. OP, definitely inspect your trimmer.

   / Trimmer with terrible vibrations #9  
I pull the drive cable out every other year and wipe it down and grease it up good and I also grease the gear drive unit a tad. It doesn’t take that long and fairly easy to do. A lot of folks ignore the drive cable/shaft lubrication.