Noise from the shaft, clacking...

I've recently had a speed-dependent cracker under the car...when the V8 is warm, it gets much quieter...when it's cold it "rashes" it for a certain time...
To form over the gearbox, it could not properly locate... With full drive it is more of a "Pruhsten"...Have Kats already had down, all heat sheets removed, Krummer controlled....what can that be? Help...