the other day i locked my cad system to resolve the vacuum problem. it went fine for a while but then i started getting this metallic clank that changes with speed. figured out its in the t case or trans because it wont do it in neutral, check all u joints and unlocked the front end and im still getting that noise. im at a loss at to what it is but im hoping its not to $$$

 

Need to find out exactly where the noise is coming from. Have you check the snap ring on the output shaft of the t-case? (gotta pull the driveshaft, and tailhousing off the t-case to see it.)

 

i havent check the ring but i have crawled under and i cant hear anything while rotating the driveshaft, front or rear. the only time it doesn't make the noise while driving is if the tcase is in neutral. if i can still here it if i put the tranny in neutral and coast. im assuming that this was caused by my front end being locked

 

check the fluid. and also the chains in the tcase strech and then run alont the bottom of the housing and make what sounds like a card in a bike spoke that being road slowly and speeds up as the truck speeds up