Blasting sand and rear end lube makes a great grinding compound! You'll need to do a full teardown on the rear end, and wash and inspect everything. That would need to include cleaning up the axle bearings, and installing new seals everywhere. Even a little sand, like 2 or 3 tablespoons full will cause major damage in a hurry.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!