Pushrods, how do I measure for...

On my solid tap it cam if my pushrods that formerly worked all the sudden became looser than I could have ajusted for with my rockers I would start thinking my cam was wiped out or my solid tap it? This is the part that I haven't personally seen that commonly just where's out. I'm not saying that it can't, I'm just saying it's usually something on either side of it. it's more or less just a solid piece that transfers motion and sometimes lubricant. If these are the push rods that were put in before then I would be of the school if they need to be changed and they were never the right ones to begin with OR it's not the problem!