I hope you guys don't mind me asking a lot of questions, but what exactly is this part? I noticed I missing it now that I am hooking the engine back up. the bracket and the cable is there but the rubber boot thing isn't there. It's on the passanger side fender just about the battery tray.(this is just a picture of what it looks like. not my truck)

 

That is the vacuum actuator for the front axle engagement when in 4HI or 4LO.

What do you mean by "the rubber boot thing isn't there"?

 

Its hard to explain, I will take a picture tomorrow as the truck is in the shop at school. like the cable is there but you see that black part its not there.

 

so what you're saying is that the vacuum diaphram is torn and missing. that would be the "the rubber boot thing" in your pic.

 

If thats what its called then yes thats what is missing.

 

ok, then you will need to get a new one for you 4x4 to work