79 Chevy Transfer Case Shifter Vibration

[spidyrmen]

AT LOW SPEEDS MY 79 3/4 TON 4X4 IS FINE. AT 55 MILES AN HOUR IT THE 4 wheel DRIVE SHIFTER STARTS TO SHAKE. AT 65 IT IS RATTLING MY TRUCK APART. THE TRANMISSION CROSSMEMBER LOCK NUTS WERE ALL FOUR THREADS DOWN. I HAVE OIL LEAKS AND TRANNY LEAKS FROM THE VIBRATION. MY DRIVESHAFT HAS A LITTLE PLAY IN IT AT THE SLIP JOINT. I DON'T KNOW IF IT IS BAD ENOUGH TO CAUSE THIS PROBLEM. I HAD MY TIRES (35X10.5X16.5)BALANCED. I HAD THE DRIVESHAFT BALANCED. NOTHING SEEMS TO WORK. I TOOK THE REAR COVER OFF THE AXLE AND FOUND SOME STEEL FINES IN IT. I TOOK IT TO THE ONLY 4 WHEEL DRIVE SHOP WE HAVE AND THEY MEASURED THE ANGLE OF THE DRIVESHAFT AND IT IS FINE. NEW U-JOINTS AND FLYWHEEL I AM AT A LOSS. ANY SUGGESTIONS? THANX