8N Over-run coupler

[jimjumper]

Have an 8N with a broken over-run coupler. It doesn't allow my brushhog to freewheel when I disengage the clutch. Any ideas on how to get it off? I assumed from looking at it you just removed the set screw and the Zerk fitting and pounded out the pin with a punch? I've beat on the end of the pin pretty good and its not going anywhere. Even YouTube doesn't have a video on removal, only installation!

 

[bmaverick]

Have an 8N with a broken over-run coupler. It doesn't allow my brushhog to freewheel when I disengage the clutch. Any ideas on how to get it off? I assumed from looking at it you just removed the set screw and the Zerk fitting and pounded out the pin with a punch? I've beat on the end of the pin pretty good and its not going anywhere. Even YouTube doesn't have a video on removal, only installation!

I take it you have the crappy overrun clutch with the shear pin. It's so old school and fails too much.
Does it look like this one?

The big problem you have is removing the rolled pin. Do you own a punch and a hand sledge?

If you ever get the thing off, do upgrade to the newer type. The new type has a simple spring loaded push pin. Using your index finger and an easy push, it unlocks to be slide off.

Overrunning Clutch-PTO Overrun Clutch

An overrun coupler attaches to a tractor's PTO shaft and drive shaft of the implement. It has a 1-3/8

www.agrisupply.com

 

[jimjumper]

That is what I am planning to replace it with but, in the meantime, it appears I have enough slack in the mowers PTO shaft that I could put that coupler on over the broken coupler and still attach the mower shaft. It might look ugly but is there any reason it wouldn't work? The broken coupler is jammed and not freewheeling.

 

[DJ54]

I'd be careful mounting them in tandem, even though you may have enough room to get it on with the mower down, it may jam the PTO shaft when raising and ruin the new overrun clutch. Now that I think about it that may be the problem now. If raised too high, or when crossing a swale, it may have jammed enough to put a lot of pressure on the clutch and has bent/partially sheared the roll pin holding it on.

If that's the case and you don't plan to rebuild/repair that clutch would be to get some cutoff disc's if you have an angle grinder and split it long ways, outer part first then carefully the inner workings so as not to damage the PTO shaft.

I have several of the old school clutches on several tractors here and never had a problem driving the pin out, but always kept them greased occasionally. If you kept yours greased, just for the heck of it I'd raise it all the way and see how close the PTO tubes come together, if close, crossing a swale could cause the above problem taking it further than the tractor picks it up. They will pivot up quite a way's beyond as high as the tractor can lift.

 

[bmaverick]

That is what I am planning to replace it with but, in the meantime, it appears I have enough slack in the mowers PTO shaft that I could put that coupler on over the broken coupler and still attach the mower shaft. It might look ugly but is there any reason it wouldn't work? The broken coupler is jammed and not freewheeling.

Do you own an angle grinder with a diamond dust wheel. I've cut off locked drum brakes in half with this method very fast.

You need to only watch for safety and not to damage the original PTO splined shaft.

 

[John0829]

I agree that I would not try to use them in tandem, Have you tried driving the roll pin out from the other side? Last time I had to remove one I had the same thing happen, would not budge from one side but moved out going the other direction. Seems that the pin had been swelled on one end.

 

[jimjumper]

I'll try a little harder when I get a decent punch. I do have an angle grinder if I end up needing to cut it off. What a PITA!!

 

[rangerfredbob]

The problem you're likely running into is the roll pin is likely not lined up with the hole for the zerk so you're just pounding at something hard that isn't right...

 

[bmaverick]

I'll try a little harder when I get a decent punch. I do have an angle grinder if I end up needing to cut it off. What a PITA!!

You are not the first person cutting one off. The area near the grease fitting, cut on that diameter long ways. Then 180 on the diamter on the other side. It should open up like a clam shell.

 

[jimjumper]

Success! I hate leaving a repair unfinished so I drove into town, got the right punch, and took rangerfredbob's advice above (Thanks!) and cleaned out the Zerk hole of grease with q-tips and alcohol. The edge of the collar was just a hair over the pin. Turned it with a crowbar and the mower hooked up and the pto in gear. A couple good hits with a persuasion hammer and it slid out. Have the new removable on order and should be here Wed. Thanks, now I can get back to the mowing. Only a couple acres left for this round. I still think my idea of just stacking them was a pretty good one though!