VOLATILE CLEANERS WERE USED TO CLEAN GREASE IN THE VEHICLE SWING SHAFT BORE WHEN IT WAS DISCOVERED THAT MODIFICATIONS HAD TO BE MADE TO THE LIP TO PLACE THE RETAINER. TARP WAS PLACED IN THE BO RE TO PREVENT DEBRIS FROM GRINDING ENTERING. IT TRAPPED GASES FROM THE EVAPORATING CLEANING FLUIDS WHICH WERE IGNITED BY THE GRINDER.