rear end on 99 astro is whining, is it ok to drive 300 mile trip ??

1) Check for leaks. Fix them. 2) Pul the rear diferential cover off to drain fluid. Check for metal/debris. 3) Refil with synthetic gear oil. I also recomend Lucas Synthetic Oil Suplement and STP. The axle on my Astro van has whined since I've has it. The front seal leaked. When I drained it it held les than a quart. I'm told the noise now comes from wear on the gears. The sound has not changed since I aquired the van. God luck, The Ammo Guy 8-) Aim small, mis small.