Hardbody Driveshaft

since i have gotten my hardbody i have noticed when the rear of the truck is at a certain height while driving there was an annoying pinging notice coming from under the truck.

i just did a carrier member bearing on my 94 short bed regular cab hardbody last night and noticed that there is a metal sleeve that looks to be some sort of dust cap that goes on the front part of the front driveshaft that covers the ujoint. i realised after i had everything back together that is where the sound is coming from. it isnt on there tight, when the rear gets to a certain point, that just pings around and makes noise.

my question is can i take it off, or is that really needed? i dont want to take it off when it really should be there.

sorry for the novel, thanks for your help.