Hate to dissagree, but I have had plastic clevises strip from vibration and come off. The only plane I use them on is gliders and my magic because all the pushrods were strange sizes and I didn't feel like changing them. If the metal clevises screw on and are the same thread, switch them. If not, keep an eye on them.

When the one stripped on me, it was on a landing approach, with just a bit of up elevator. You never know when they will come out. Use metal unless you can't because of rod size.