There is a noise coming from some were on the frontend of my 90 K5. I check the T case mount, all U joints, shock mounts, and everything else I could think of. It only makes the noise when it is in 4whl and the noise is worse when I go in reverse and turn. The noise is a klancking sound that keeps pace with the idle of my blazer. I first noticed it when I was going through an alley in town that had about 12" of snow. Any body got any suggestions?