so sometimes when i accelerate from 2nd to 3rd i get a loud clank in my rear. i thought it was a ujoint but there is not play in them at all, but i do have about a 1/16 play when i turn the drive line. this only happens when i have a dead spot when the tranny shifts and makes a loud clank sound. never noticed it till i ripped out the head liner and rear plastic panels. i have a 05 chevy extended cab 4x4. i really dont know what the deal is but i would kinda like to know what to look for when i get time to tear into it. probaly take the rearend cover off to check the gears and the front slip to check the splines. thanks for any input.

 

I wouldn't worry about it they all make that noise on the 2 3 upshit at 25 to 30.