Seeing the type of clip... Now I can see that it is very unlikely for it to fail. As mentioned, the issue, IMO, lies in the groove diameter, width or possibly the cross section of the groove. With that said if the wrong clip is used that could also be the problem. My vote would be for the groove to be incorrect. I've always felt the clip should be a tight fit in the diameter. if you can easily move the clip with a pick, it is to loose. The clip should have some drag in the groove.

Here is a link to a chart showing correct ring and groove dimensions. English- http://www.arconring.com/stamped-ret...ings/internal/ Metric- https://www.rotorclip.com/cat_pdfs/dho.pdf

There is also a correct and incorrect way to instal the snap ring. The "square" side of the ring should be placed away from the force pushing against it. In a wrist pin application the square side should face out.

Ken