i took my z71 through some thick mud this past weekend and wen i got out and went to turn around i heard a click click pop sound from my left front tire and now while im driving it just rattles like crazy so now ive parked it ...i didnt see any obvious damage when i pulled the tire off but it continues to make the the rattling sound..im thinking the u-joint that drives the left front while in 4wheel drive has screwed up in sum way but wanted to get a second opinion before i started pulling things apart.

CLAY  

Is this stock or lifted with big tires as this will give me some idea as to what might have happened or failed.  

sounds like your cv shaft (half shaft)...mine made the same noise on the right side, sometimes the joint will explode inside the boot.  

keithpapa:
sounds like your cv shaft (half shaft)...mine made the same noise on the right side, sometimes the joint will explode inside the boot.

I tend to agree but I am just trying to get bigger picture here.  

the truck is all stock suspension. only mod is a high performance motor...about how much would it cost to have it fixed   its the joint that connects to the hub...would it b ok to drive the truck with this problem or just keep it parked until i can get it fixed?  

Well did the joint explode or is the boot torn and grease puking from boot? if not then it should be ok if your not in 4wd...BUT do get it fixxed before you need to use it.