I assume that you are old enough to have really been around those things when they were new. I was not, so I can't say for sure. It's quite possible that when they were new that they did in fact stop under the right conditions. What follows is a copy and paste of a reply that I just left below under the "6000" post: "I found that when I rebuilt those trannies that if I set the bearing preload for the PTO clutch pack to the tight end of the specs, that the shaft would stop when the oil was warmed up and the engine at idle. Sometimes the hold was so tenuous that the shaft would take off again if you revved the engine up. Bottom line is this: 99-plus percent of those SOS transmissions will spin the PTO with NO load attached. The degree (torque value) to which they will spin a load depends on many factors, among them being oil viscosity, temperature of the oil, condition of the clutch pack (plates flat or warped), speed of the engine, and the tightness (pre-load) of the bearings." Yes, I have seen them stop, but they were few and far between. I'd be interested in hearing from anyone else on this board who may be reading this if they have an SOS (5000's excluded) that will hold the PTO shaft stopped, and if so, under what conditions will it do that. If I were a betting man, I'd say that it would in fact NOT hold if the oil was cold and then engine revved much more than half throttle. There simply is nothing there to stop that clutch pack other than the pre-load on the clutch shaft bearings, and that may have been what the engineers were thinking when they designed it. Too bad they're all dead (this tranny was designed in the mid 50's) or we could track them down and ask them.
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