I just went through this massive saga with all this stuff. I had to get a new tail shaft and diff yoke cause i left it too long, you should change the couplink as soon as possible, it cost me a hundred bucks for the couplink by itself and all of it only took me half an hour to change, but that was with all the extra stuff as well (being a new tail shaft and yoke) man it was worn out, just do it asap to save money hey