I HAVE JUST HAD THE REAR END IN MY 64 C10 REBUILT. I USED THE HOUSING AND AXLES FROM A 70 CHEVY AND REPLACED ALL BEARINGS AND SEALS. IT DRIVES GREAT NOW EXCEPT IT MAKES A HOWLING SOUND. IT ONLY DOES IT AFTER I GET UP TO SPEED AND IM KIND OF FLOATING. IT DOESNT MAKE ANY NOISE WHEN I'M COASTING OR WHEN I'M TAKING OFF.
THE MECHANIC SAID THE FACTORY GEARS ARE IN PRETTY GOOD SHAPE EXCEPT FOR A LITTLE WEAR.
WHAT COULD BE CAUSING THE NOISE? IT DIDN'T MAKE IT BEFORE.