Impact driver issue: Intermittent springy/twang sound

Question

I suspect my impact driver is starting to bust.

Every so often, I hear a soft 'twang' sound shortly after pulling the trigger. I don't remember hearing it in the past, but I'm not 100% sure, maybe I never noticed. It doesn't seem natural anyhow.

The unit still does work, regardless of the twang sound, however it seems to be challenged with some tap-cons recently that it shouldn't have a problem with. I couldn't get the screws in 100%. This was with a client, it was embarrassing. I double-checked the holes were deep enough and the screw diameter matched, everything was ok. I was perplexed.

Just now tested a thick 3" screw into a 4x4 and it seemed to be challenged getting it down all the way, and just not sounding right.

Do impacts slowly fail/degrade, or am I imagining things? Or do they typically just fail and stop working one day?

Makita LXT 18v cordless, lots of use.

Answer 1

A little late to the party, figured I would share an image I found while researching my own impact driver's issues.

I'm guessing that your "twang" isn't associated with the trigger mechanism (or you'd probably have figured that out already). The hammer mechanism has to have a spring to restore the hammer back away from the anvil, and after a lot of use I'm sure the spring can get fatigued. I'll post images of my impact driver once I pop it open and get this section exposed. In the meantime, check out this site below:

https://eztoolhub.com/ultimate-guidelines-in-repairing-a-cordless-impact-driver