What was found
AT LAST OVERHAUL, INSULATION SLEEVES WERE INSTALLED AROUND THE 4 THROUGH-BOLTS WHICH HOLD THE UNIT TOGETHER. THE INSULATION ON ONE OF THE BOLTS CAME IN CONTACT WITH THE ROTATING ARMATURE. THREE-FOURTHS OF THE INSULATION WAS DESTROYED SENDING FIBERS THROUGHOUT THE STARTER. FIBERS FOULED THE COMMUTATOR END OF THE ARMATURE CAUSING PREMATURE BEARING AND SHIM FAILURE.