over running PTO clutch question

I have an old AC rotary mower that has an over running clutch on the PTO shaft. It is worn out and no parts are available any more. If I weld it solid will it harm the PTO on my tractor currently I use it behind my 1855. Should I use one of these over running clutches you can buy at a farm store. thanks Mike
 
Seems like to me your are talking about two different things here.
1. It sounds like you mean the slip clutch in front of the mower gear box. This is meant to slip or take up shock if the blades were to hit somthing quite solid. I would update it with a newer one slip clutch, not weld the old one together.

2.An over running clutch (one way clutch) will not protect your tractor. That is only there to absorb inertia from the mower when you decellerate or take the PTO out of gear. The mower acts like a giant flywheel. On earlier model tractors without independant PTO the mower's inertia can actually backfeed power thru the pto into the transmission and keep the tractor moving even if the foot clutch is pushed in. Thus making the tractor hard to stop, especially in an emergency situation if an overrunning clutch is not used. Like I said the overrunning clutch will not protect your tractor if you hit something with the mower. I hope this makes sense.
 
Yes, the Allis mowers did have an overrun clutch built into the power shaft. This was a feature that I really liked about it. Personally I would repair or replace the shaft and purchase an overrun, There is a lot of energy built up in the blades and with an overrun, this will reduce the shock to the tractor's P.T.O. when you throttle down or shut the pto off. It will also help prevent the cutter from tring to "push" the tractor
 
Thanks for the input. The pto shaft has both a slip and an over running clutch. Slip clutch I was familiar with and it works as it should. Over run however is worn out where the spring loaded pins will not catch and drive the shaft. Thanks again
 
A few things to consider in addition to the other responses. Remember that even fairly late model Allis tractors did not have true "live" pto like your Oliver does. If you wanted to change gears, you pushed in the clutch and the transmission was still coupled to the PTO. Hence, the tractor could be pushed and it was almost impossible to change gears until the mower spun down. This is why the put in overrunning clutches.

Your Oliver is totally different. You can clutch, change gears, do whatever with the transmission and it's basically 100% decoupled from the PTO hence eliminating the need for an overrunning clutch.

In addition, even when shutting off the implement, the PTO on your 1855 includes a wet type fiber brake of a single plate design. This brake can handle a reasonable amount of slipping associated with stopping a high inertial load. We have a 720 Woods and there I've had no issue applying the brake with the mower going full tile. That said, the best method is to shut off the PTO wait for it to spin down a bit, then engage the brake.

Moral of the story, that overrunning clutch is unneeded with an Oliver and is just another liability.
 
I would wonder how many of those parts really are parts only available through Allis (or no longer available). I rebuilt an ORC on our NI 290 haybine as the pins and the sleeeves they were in were worn. The sleeves were more or less a drill bushing for a 1/2" drill bit, and then the pins were dowels.

I milled the sleeves out and pressed in new ones, and then the dowels just needed to be polished down with some emry cloth so they would slide freely inside the drill bushings. I think the total cost with new pins, sleeves, and springs, was under $20.

Donovan from Wisconsin
 

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