NDDan
Guest
I won't say any upgrades to this area wouldn't be OK. We just have never spent a whole lot extra to do it. No matter what design you have the same old thing comes to mind (get the nut tight). I can't quit say but I believe your S_N would have the slightly smaller bearing. To use the slightly larger bearing you need the newer shaft and bearing holder. With the larger bearing the torque on nut was raised from 450 to 600 ft lbs. We have paid special attention to torqueing that nut for many years now and I have to say we have not yet had to pull a mainshaft from a R62-72 predelivered at our shop. Yes we have replaced a few bearings but never damage to shaft. We have replaced a few shafts but all them machines come to our area from the outside. I feel quite bad about one of them for we did check his nut torque but the unfortunate thing is the thing had been loose at one time and then froze up tight from the metal erosion and rust. Then tightening the nut didn't crimp the all ready loose inner race of bearing back to shaft. I've desided it would be a good idea to just pull varible from one of them machines that come in from the outside and pull varible to be sure everything is going to tighten up when nut is torqued. Oh well must live and learn. Good luck.