I bought a cat 267b about a month ago. It's been working great, I've been moving a lot of dirt to build a house pad... yesterday I'd do some brush hogging for a couple hours then started moving dirt. I was just about through piling dirt and the loader started making a kinda low tone growling noise while under a load scooping up dirt. Couldn't tell for sure what side it was coming from. Any idea what it might be? The loader didn't feel like it lost power. Thanks.