Some '94 R62 72's got the larger bearing at plant and all '95 or newer got larger bearing at plant. '94 machines with factory installed smaller bearing and earlier machines may of had shaft updated to larger bearing setup. I would believe parts book on CD have these misprints fixed and or worded more clear. We've never yet had a mainshaft out of a R62 or 72. We have had bearing go out there a few times over the years but never spun on shaft for we we're sure to torque up varible nut to specs right from the get go. lots of our hours at high HP requirement are put on with high cylinder speeds which would cause less put on that bearing. low cylinder speeds with high HP requirement would pull harder on that bearing thus likely cause more failures. Anyway the so called small bearing is still bigger than the 270HP N7,R7,and R70's used and they never gave us much trouble either. Them older machines had a slower speed mainshaft also which would of caused more pull on mainshaft for a given HP requirement. Anyway be sure to get the big nut tight and allways have operator pay attention to their senses and shut down if something is getting goofy.
