procomps shocks are junk and notoriouse for the press in rubber bushings getting sloppy after a while. check both bushings(upper and lower) on both shocks and see if they feel loose on the mounting bolts.

 

thanks for the response. The rear shocks were replaced with bilsteins, and everything is tight.

 

Bump for the early morning crew

 

Rattle is still there, I thought it might be my brake lines but that wasn't the problem either. I am completely stumped on this one.

 

its the joint between your rear differential and the connected end of the driveshaft

 

Ahh I got ya. how would I check and see or figure out if it is going bad?

 

Jack up the rear end, put your trans in neutral, have someone turn the wheels while your hand is on the driveshaft. there should be no slack or "lag"

 

do0uble post

 

Thanks man. Could that be the rattle im hearing if the u-joint is in fact bad?

 

possibly, if its bad than yes

 

Holy crap guys, learn how to quote already!

I'll clean up your quoting mess when I get home from work.

 

I don't know if you already fixed this problem but if you haven't maybe this might help... A couple of days a go I took my '04 FX4 to have the undercarriage cleaned. In the morning I noticed a very loud knocking just when I turn (to either side) or when I hit small bumps also when turning. It sounded like the spare tire or the muffler where loose. A couple of hours a go I came back from a friends garage who took a look at everything from the wheels to the differential to the trans axle only to tell me that everything was ok. So, I ask a friend to move the truck back and forth to see if I could hear the noise myself and try to locate it... as it turns out we did, it were the spring leafs that got to damn clean and where making that noise when rubbing. I put some WD40 in between and the noise is now gone... Hope it helps man.

 

I got the same sound. I sprayed white lithium grease on the spring joints. Its probably too thick to get in between the springs. I will try wd-40.