Posted by David Sherman on Thursday, April 05, 2007 at 01:17:19 :
In Reply to: Starter Drives work by friction- posted by chriscase on Wednesday, April 04, 2007 at 18:48:54 :
Mine doesn't have the helical shaft -- it's a straight spline -- but I've seen some that do. I guess this kind just depends on the overrunning clutch to keep from spinning up the starter too fast if the pinion doesn't retract. My old D4 Cat has a different mechanism to solve the same problem: you manually engage the pony motor pinion to the diesel engine flywheel with a clutch that snaps in place against spring pressure. The pinion has a mechanism similar to a fly-ball governor in which at a certain speed the arms fly out against spring pressure and release the pinion to spring back away from the ring gear. You can adjust the actual disengaging point so that it's just a bit faster than the governed speed of the pony motor. It must not be foolproof, though, because when I got the Cat, the pinion gear was all torn up and I had to get a new one.
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