Slip clutch - shear pin ?

   / Slip clutch - shear pin ? #1  

erda

Bronze Member
Joined
Aug 14, 2014
Messages
64
Location
Alberta
Tractor
Kubota B2601
So, just wondering what the pros and cons are of each, specifically on a rough cut mower.
 
   / Slip clutch - shear pin ? #2  
When you break a sheer pin, you have to replace it with a new $0.25 bolt.

When you hit something with a clutch, it slips & you cary on. Every spring you have to spend an hour or so loosening up the pile of bolts holding it together, engage the PTO so it slips & frees up the clutches that have rusted together. Shut things down & tighten the bolts back up the same excact number of turns you loosened them.

I thought I got a slip clutch on mine, but when I got ready to do my first spring maintnance, I was disappointed to find I had been mislead by my dealer & it was just a sheer pin hiding under the shields not the clutch they said it was. Still torqued at the dealer, but the simple fact I don't have to wory about doing any maintnance on it & have yet to sheer a pin make me not regret having the pin.
 
   / Slip clutch - shear pin ? #3  
I have the slip clutch on my cutter and as Fallon said, I took mine completely apart recently to check the wear on the clutch plates. It is a little easier when cutting as you do not have to stop to replace a pin but does require some maintenance at least once a year.
 
   / Slip clutch - shear pin ? #4  
On my five ft.Bush-Hog branded BH I have a shear pin and have only sheared them twice in five hundred hours.My new six ft. Landpride has a slip clutch;dealer said they were having problems on start-up with the shear pin models.
As stated;due your spring service on the slip clutch before use.It is not a real big deal really.
 
   / Slip clutch - shear pin ? #5  
For about ten years I had a sheer bolt on my 6ft Landpride rotary cutter. I carried several spares in my tool box and on some days, would use them all up. I'm brutal on my mower and if I can run it over, I'm going to try to cut it down. I've replaced the drive shaft a couple times now and just this year decided to try a slip clutch. I ordered it from Messicks.com and forget the price. It was more then the regular drive shaft, but I figured if it meant less time replace sheer pins, then it would be worth the cost. After putting about 20 hours or so on it, I am very impressed!! I love how it will slip a little, but then grip again and keep on cutting. That little big of slippage has made a huge difference in how much I can get done while out mowing. I just wish I had bought one sooner.

Eddie
 
   / Slip clutch - shear pin ? #6  
It depends on your application. Light cutting will favor the shear pin because the pin will hold up and be ready for the infrequent surprise. In general cutting where conditions vary greatly the slip clutch will keep you in the seat making progress no matter what. The clutch will slip with impacts w/o you knowing it usually. Every one of those is another shear pin. Only when you really jam the cutter up will you detect clutch slip. Quick action is necessary to avoid undue wear or damage to friction plates in the clutch in these cases. If the banging stops suddenly and the tractor keeps running check NOW.
larry
 
   / Slip clutch - shear pin ? #7  
Just mowing my 5 acres of pasture & a bit of the road side in-front of my & neighbors places I have yet to sheer a pin. Not very challenging mowing really, but I occasionally bury the blades into some dirt & mowed over a 6' high dead pine about twice. Yet to sheer a pin in the maybe 50 hours of mowing I've done. Hit a thumb sized copper grounding rod barely sticking out of the ground once, chewed up & bent the rod pretty good, but didn't sheer a pin or really slow the mower down much. Probably would have been a different story if it had been a steel rod or a bit thicker.
 
   / Slip clutch - shear pin ? #8  
A slip clutch is usually found on better machines.
Shear bolt on cheaper machines.
It partly depends on how big of tractor and how big of mower you are using. If you are running over 45-50 PTO HP I would buy one with the slip clutch.
Below that you will probably do ok with the shear bolts.
 
   / Slip clutch - shear pin ? #9  
Like Eddie, I would go through a handful of bolts on some days and now use only cutters with slip clutch, sure saves me a lot of time.
 
   / Slip clutch - shear pin ? #10  
I can adjust my slip clutch in 15-20 minutes, not an hour. Once you do it a couple of times, it's no big deal.

If you're just mowing pasture, a shear pin will be fine. The only caveat on pasture mowing, at least around here, is fire ant mounds. We have them all over the darned place, and they are a nuisance when you hit them without knowing they are there.
 
 
 
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