NV4500 noise

[sctrailrider]

I got my tranny changed out today, put in a NV4500, kept my NP241 case, everything went good with the install. The tranny is used, I didn't hear or see it run before getting it, I did remove the PTO covers and had a look inside, nothing seen wrong, no parts in the bottom, when I took it for a check ride it shifted great but when the truck is sitting out of gear there is a "deep rattle" until the clutch is pushed in then the noise stops... what should I check to find the noise?? I reused the T/O bearing and put a new pivot ball in.

What is the noise I am hearing ???