Many OEM starter motors have an unprotected output needle bearing on the outside of the output shaft's seal; moisture can and does enter the output cap of the electric motor and follows the armature shaft to the unprotected output needle bearing, which corrodes the bearing
Rick's takes the extra step of installing a double-sealed ball bearing, with the output shaft seal on the outside of the bearing in their new aftermarket unit
This simple application of common-sense engineering does two things: first, the outside bearing is now protected from damaging water entry, and second, the sealed ball bearing is replaceable
