easiest way to check u joints

Can someone please give me some tips on

1 Where exactly the u joints are on my driveshaft (pics would be great)

2 How exactly should I check them.


I plan on checking every nut/bolt under the rear of the car today and I think the dogbone may have something to do with it, but...


I am still trying to get to the bottom of my clunk! If you didnt read any of my other posts, it originates in the rear, travels up the driveshaft, you can feel it in the seats, and started after changing the rear control arms upper and lower.


Thanks

Thank you sir...