Does the steering make a popping noise when you get the bump feeling? If so its the steering shaft. If it is loose and bumping you may have tie rod/ball joint problems. Jack the front of the truck up and hold your front tire at 12 and 6 and see if it wiggles. It should not, if it does you have upper ball joint issues. Now hold the tire at 3 and 9 o'clock and wiggle. If it move alot, you have tie rod issues. Now, take a pry bar and place it between the tire and the ground. Lift upward, if you have any movement other than suspension flex you have lower ball joint issues.... hope this helps

 

I have an 04 half ton regular cab 5.3 v8...I currently have 63,000 miles and I replaced the water pump ($500 approx. at a shop) with about 45,000 miles on it...like the next day I heard the squeak you are talking about...I took it back to the shop and questioned it...they got the truck in and brought me back in the garage to show me that it is actually the altenator that does the squeaking on mine...quick way to check it... use a small screw driver with the engine running unplug the pigtail that goes from altenator to take load off of it...squeaking immediately stopped...the shop said that it a sign the altenator is going out but don't replace it until it strands you somewhere because it may go another 100,000...I notice mine squeaking not all the time but only on really humid weather days. The tensioner of the serpentine belt also seems to go on GM products...it is more of a rattle...they are pretty cheap fixes b/c they just push a new bearing in them...my brother in law did the last one I needed done...not on the truck! Enjoy your new ride! Prepare for a hit on wallet at Gas Station...mine is 35 gallons at a time!
Mudslinger2

 

so far so good on the truck. iv been getting about 14-15mpg pulling a 4x8 trailer.

iv also been busy adding led lights. i was gona get aftermarket led cab lights. but i got oem ones insted that belong on the 07 and newer gm pickups. i think they look better. gm wanted least $60 for a wire harness. but i made one for about $20 to meet my needs for the extra 2 led cab lights. iv added so far:

front led bumper lights w/led turn, run, and white running/daytime leds.
rear led tailights
rear led licance plate leds
roof/cab leds 5 total. 2 left and 2 right 1 center.so total of 7 led clusters.

gona get:

rear under tailgate led strip
front under the bumper leds
under the door left an right side leds
bed rail leds
topper (anyone have a fiberglass white one for sale??)
astrostart

pics so far:

 

Your intermediate steering shaft is what makes your steering sound like there is a bobble head stuck in there. Here's a nice fix. Unbolt the two steering shafts under the hood. The bolt is right in the middle of the two shafts. Take the one closest to your firewall and pull it down and up about ten time to re work the grease. Shoot some white lithium grees up inside it too. My 06 did it bit my 04 does not. But when I did this it worked great. This is all the shops did. There are aftermarket and gm shafts out there now but they are about $100 and this is the free fix!

 

alright ill check into it. i havent really drove it much in the last few weeks. iv been working on putting a car starter in it. so the dash is all tooken apart for that. been also adding leds to it when i have time in between my 2 jobs. and dont look like ill have much time in the near future either. been almost working 12hr days. woek work work..... or well $$$$$$ for me......