My impact gun keeps stalling under load – any ideas?

Hey guys, I'm having trouble with my Ryobi 18V 1/2" impact wrench. It's only a few months old but lately it stalls out when I try to loosen lug nuts or other heavy bolts. The battery is fully charged, and it works fine on lighter stuff. Any idea what's going on?

Check the brushes if it's brushed motor, or maybe the clutch is set too low? Some impacts have a torque selector. Also, are you using a good battery? I killed a couple of my cheapo ones by pushing them too hard. Try a fresh OEM battery if you've got one.

My Ryobi did that when the anvil got slightly rusted inside. Pull the socket and give the anvil a few spritzes of WD-40, then work it back and forth. Also make sure the battery contacts are clean – I had a piece of dirt causing intermittent power.

Thanks, I'll try the WD-40 trick and check the contacts. It's brushless so no brushes. Clutch is set to max. I only use Ryobi batteries. Hope it's just some gunk. Will update after I try it.