I put a number 6 or 8 (can't remember which size) stainless washer in the pivot part and now it tightens up fine. I had the same problem before with my californians. I got the convex lenses which help. While the view isn't good by any means, it's much better than the stock 280z mirrors, plus I have a passenger mirror now also. These cars are just hard to find any mirrors that work. I pushed them as far forward as I possibly could on the door, so they are at a better viewing angle, which I think is a must, as the Z mirrors were too far back. I had the same problem on my last car which was an old roadster, and ended up using Yamaha motorcycle mirrors.