Whirlpool Washer making grinding noise

Whirlpool washer 7 years old making a loud grinding noise at the beginning of spin cycle. The grinding noise last for about 1 minute then stops after the speed increase and the spin cycle continues as normal. I also noticed a dusting of some black residue under the washer when I moved it out. Any idea’s ? Trying to decide if I should have a repairman come out ($79 plus $$) or purchase a new/used Machine.