As Fred pointed out earlier, thin retaining rings that don't
fit the slot could bend or deform. Even though there should be
very little axial load on the pins, if your going to use a
retaining ring then go with the thick heavy duty ones as noted
in the link. To work properly and prevent axial displacement,
they should be matched to the width of the slot.
The problem with using retaining rings for us, is trying to
find a source for the right ones in small quantities.
e-clips or better yet, external clip rings would be my choice
if I could find them in the correct thickness.

dg

Denny G
Sandwich, IL