I have 2001 Chevy Blazer 4 x 4 4.3-liter engine. I took it to a mechanic in late October. He fixed a problem with the fuel injection module and related problems. Usually he lets me know if he notices anything else that might be going awry.
In the last two plus weeks, I have noticed a grinding that seemed to be front end and associated with the revolutions of the wheels (my hearing is not 100%, so it could have been going on longer, but not longer than before my visit to the mechanic),. I could only hear it at lower speeds, and the noise increased when turning either direction, I think, but especially turning left. A year ago, I replaced the left front bearing hub. With this grinding sound, I figured that the other front bearing was going out--the sound seemed to come from the right side. So a week ago, I replaced the right bearing hub. Afterward, when driving, I notice this grinding only when turning left, never when turning right, and I do not believe that I can hear any such noise going straight, whether slow or fast.

While I replaced the bearing hub, I handled and inspected the axel boot nearest the right wheel. It seemed to be in good shape without any material failure. What's more, the frame below it was fairly clean, with only some fallen grease from the wheel when the vehicle received a front-end alignment last June. That mechanic was very liberal with the grease on the back side of the wheel. Last night I raised the right front wheel to crawl under and inspect the other boot on the right front axle. It seemed fine. It did not feel brittle, and what I could see and feel gave no evidence of deterioration. Surrounding hardware appeared fairly clean and not worse than expected road grime. It was not greasy.

I checked the engine mounts preliminarily by watching the engine through the gap below the raised hood as I moved the gears through reverse,, neutral, drive, and reverse. I had just replaced the engine mounts in my brother's 2006 Chrysler Town and Country (except the rear, which will be completed in the next few days. His engine mounts were in very bad shape, and I remember the engine movement, which was even more if he accelerated the rotation of the wheels in either direction. The engine movement of my Blazer is slight--not anything like my brother's. His car had grinding much like mine, which went away as we supported the oil pan on his Town and Country. I have not done that on my vehicle. I have four jack stands, but level surface is hard to find aound my place.. I can do the garage, by pulling my wife's car, so I can do that.

So explaining this reminded me of the one idea, which would likely check the engine mounts. I am wondering what more would you suspect and how you would go about diagnosing the problem?

mkl