inner CV axle snap ring replacement?

Just pulled the CVs out, and was reading some people recommend replacing the snap ring on the inside of the axle that secure the axle in the diff. Some people seem to not mention it. My snap ring is still on there, but doesn't look very tight- as in I can spin it around super easily and move it up and down a bit although it is not coming off without tools. I was expecting it to be more snug, so this is why I'm asking for any advice on wether it's crucial to replace this or not. It could just be this way and I haven't noticed before. That, and nobody around here has one in stock and it'd be Tuesday before I can get one...

 

This looks like it's implying to re-use the snap ring

http://www.4x4wire.com/toyota/maintenance/cv_axle/