I have a weird cracking sound when braking at near stop. Been reading about the rivets coming loose on the cross member but I don't see rivets anywhere. 06 F150. Am missing something?

 

Rock the truck from side to side and see if you can locate the source of the noise. On my 1993 it was the left side rear spring support located on the front of the spring and riveted to the frame. Rivets were tough to get out. Drilling was a nightmare, grinding the heads off and using a 2lb hammer and punch worked fine.

 

Only happens driving and braking. Can't replicate rocking it. For the life of me I don't see any cross member Rivets anywhere. Does this year not have rivets?

 

Just to add a little detail.
My 1993 I had a creaking sound when coming to a stop and occasionally when going over a bump, sometimes it was more of a pop. Over a period of a couple of years, I had the truck into three different front end shops and none of them could find the problem. Noise sounded like a bad ball joint but worse.
I accidently stumbled across the problem and it turned out to be a problem towards the back of the truck as opposed what I thought was a front end noise. The spring support was rusted and had failed as shown in the attached photo. On the 1993 the support for the rear spring were riveted to the frame. You can see some of the grinder marks on the old support where I ground the heads off of the rivets. Newer support came from a U-pull yard in Mobile Alabama and took quite an effort to get the spring back in place so that the pivot bolt would fit through the holes. Newer support was bolted to the frame using grade 8 bolts.