If in all this you've never checked all the drive pins - its time.

While its upside down, take your 2mm driver and find the small half moon cutouts in the skids. There are 2 on each end, one on each side. This is the hole you tighten the drive axle drive pins through. Get a light and rotate wheel until you have the socket end of the drive pin lined up with the hole, make sure each one is tight.

I don't use these plastic 3.3 cvds for center drives, but now that you see what's involved, make sure you check them as well. I check my driveline prob every 6 or 8 runs, I might over do it, but its peace of mind.