We have now had the second Leroy Somer motor shaft shear off where in enters the gearbox. First the outhaul 2 years ago, and now the mainsail furler. Sheared at same location. Rust evidence of possible stress crack that eventually left maybe 10%-15% of the shaft in tact that then sheared off. Aletes is 20 years old. Has anyone else experienced this? Had a spare for the first failure, now sourcing a replacement for the second failure.