Slip clutch

[Bonaro]

I am learning about tractors the hard way...
Kubota L275 + 5' Bush hog mower + hidden stump = broken PTO shaft
I found a replacement PTO shaft and also ordered this wonderful device called a slip clutch

I understand that sometimes these clutches will rust up and you have to loosen the springs and slip them to make sure it will work. Is there something I can treat the clutch discs with to prevent rust?

 

[GeoHorn]

I am learning about tractors the hard way...
Kubota L275 + 5' Bush hog mower + hidden stump = broken PTO shaft
I found a replacement PTO shaft and also ordered this wonderful device called a slip clutch

I understand that sometimes these clutches will rust up and you have to loosen the springs and slip them to make sure it will work. Is there something I can treat the clutch discs with to prevent rust?

THis is a detailed, and complicated answer so hope it’s understandable; No.



(Sorry... couldn’t resist...). The best thing to do is to store it under-cover or at least cover the clutch with a bucket Or such.)

I’m surprised your old drive-line didn’t have a shear-bolt... Or pin...?? Or perhaps someone substituted a bolt or pin which was of the incorrect hardness...?? A grade 2 or 5 bolt or a roll-pin is usually the requirement on non-clutch-equipped attachments.

 

[Henro]

I am learning about tractors the hard way...
Kubota L275 + 5' Bush hog mower + hidden stump = broken PTO shaft
I found a replacement PTO shaft and also ordered this wonderful device called a slip clutch

I understand that sometimes these clutches will rust up and you have to loosen the springs and slip them to make sure it will work. Is there something I can treat the clutch discs with to prevent rust?

Everyone cannot store all their equipment and implements under effective cover.

If you search here for slip clutch or something similar, you will find threads addressing the issue. There are things you can do to verify the slip clutch is operating/in operating condition.

I do not remember the exact procedures, but something like marking across the clutch with paint or a marker, loosening the bolts that produce clamping force between the clutch plates, causing the clutch to slip, and torquing the bolts back properly.

 

[Crash277]

Everyone cannot store all their equipment and implements under effective cover.

If you search here for slip clutch or something similar, you will find threads addressing the issue. There are things you can do to verify the slip clutch is operating/in operating condition.

I do not remember the exact procedures, but something like marking across the clutch with paint or a marker, loosening the bolts that produce clamping force between the clutch plates, causing the clutch to slip, and torquing the bolts back properly.

That's a very good summary of what my tiller manual states to do after removing it from storage.

 

[GeoHorn]

”everyone cannot store...under ...cover”
... That’s why I also offered the suggestion of covering the clutch with a bucket.... I store my vehicles, tractors, side-by-side, etc inside.... but my shredder lives out under the trees.... with a bucket covering the slip-clutch from the rain/elements.

On another thread, the discussion centers around gear-drive tractors and their clutch ... it being suggested to store those tractors with their clutches “depressed” so as to avoid the plates from “sticking” and creating a problem of being permanently engaged due to rusting. A similar thing applies to a slip-clutch... if moisture/humidity exists....it can “stick” or “weld” the clutch plates rendering the clutch inoperable for saving your tractor PTO-driveline from sudden-stoppage.
The only way to assure it will work properly is to prove it at the beginning of the season I’m afraid.

 

[SDT]

I am learning about tractors the hard way...
Kubota L275 + 5' Bush hog mower + hidden stump = broken PTO shaft
I found a replacement PTO shaft and also ordered this wonderful device called a slip clutch

I understand that sometimes these clutches will rust up and you have to loosen the springs and slip them to make sure it will work. Is there something I can treat the clutch discs with to prevent rust?

Again, no.

It matters not whether the mower is stored inside or not, a slip clutch must be slipped occasionally to prevent corrosion lock.

Loosening and slipping annually will suffice.

Consider yourself fortunate. It's usually the gearbox or tractor internals that fails rather than the PTO drive shaft.

SDT

 

[UpNorthMI]

I learned the hard way with a rusted slip clutch. I purchased an older used heavy duty woods rotary cutter, went well for a couple of years until I let my teenager clean the trail edges. It was on the back of my MX5800 and had a 65/70 hp rated gearbox. My son got ambitious in cutter back the trails wider than normal, he hit a raised bit of ground, it destroyed the pto shaft (bent) and gearbox (input shaft blew bearings from housings, blew top and bottom seals) also bent diagonal braces on attachment from top link connection point, luckily no damage to tractor. New pto shaft with slip clutch and new gearbox complete now work well!

I now loosen up, slip drive run (polish up the slip clutch parts) and set all slip clutches on the first use of an attachment each year even though I store them inside.

We were lucky it was only time and parts money on the cutter it could have been worse!

 

[Bonaro]

Everyone cannot store all their equipment and implements under effective cover.

If you search here for slip clutch or something similar, you will find threads addressing the issue. There are things you can do to verify the slip clutch is operating/in operating condition.

I do not remember the exact procedures, but something like marking across the clutch with paint or a marker, loosening the bolts that produce clamping force between the clutch plates, causing the clutch to slip, and torquing the bolts back properly.

I will search the forum when I get back to my PC.
After you loosen the springs and slip it, how do you know you put it back to the proper torque without a lot of trial and error

I learned the hard way with a rusted slip clutch. I purchased an older used heavy duty woods rotary cutter, went well for a couple of years until I let my teenager clean the trail edges. It was on the back of my MX5800 and had a 65/70 hp rated gearbox. My son got ambitious in cutter back the trails wider than normal, he hit a raised bit of ground, it destroyed the pto shaft (bent) and gearbox (input shaft blew bearings from housings, blew top and bottom seals) also bent diagonal braces on attachment from top link connection point, luckily no damage to tractor. New pto shaft with slip clutch and new gearbox complete now work well!

I now loosen up, slip drive run (polish up the slip clutch parts) and set all slip clutches on the first use of an attachment each year even though I store them inside.

We were lucky it was only time and parts money on the cutter it could have been worse!

yeah....it wasn't the PTO drive shaft. It was the PTO output shaft on the tractor that let go.
At least I am pretty certain of this. I am waiting for parts to arrive before a dump 5 gallons of oil

 

[Bonaro]

I ordered a slip clutch (extension) and plan to mount it permanently on the PTO output on the tractor. My thinking is I will have one clutch to adjust for all of my implements attached thereto.

 

[SDT]

I will search the forum when I get back to my PC.
After you loosen the springs and slip it, how do you know you put it back to the proper torque without a lot of trial and error


yeah....it wasn't the PTO drive shaft. It was the PTO output shaft on the tractor that let go.
At least I am pretty certain of this. I am waiting for parts to arrive before a dump 5 gallons of oil

You don't, nor do you know that it was properly adjusted initially.

Indeed, a slip clutch should be adjusted to the equipment with which it is used before first use. Installation instructions will have procedures therein, yet nearly no one does this.

After initial adjustment, one simply counts the turns upon loosening and restores the the spring clamps to the same position. Of course, this is time consuming and few take the time to do so.

Bottom line: Shear bolt protection is much less maintenance intensive.

SDT

 

[UpNorthMI]

I agree with SDT that a shear bolt is a lot simpler, but would suggest that shear bolts should also be removed at the beginning of a season of use for an attachment and that whatever type of surfaces involved are cleaned to ensure that the shear bolt is the only real resistance. I often end up greasing or lubricating those surfaces to ensure the shear force required works correctly to protect things, there is often a grease fitting at this point but removing the shear bolt and slipping the connection cleans things up. For me this work takes place normally in April unless it is snow removal attachments.

a few minutes or half hour of work can save a lot of issues and costs.

 

[kubotafreak]

I am learning about tractors the hard way...
Kubota L275 + 5' Bush hog mower + hidden stump = broken PTO shaft
I found a replacement PTO shaft and also ordered this wonderful device called a slip clutch

I understand that sometimes these clutches will rust up and you have to loosen the springs and slip them to make sure it will work. Is there something I can treat the clutch discs with to prevent rust?

I know you said you bought a new shaft, but Agri supply has a good list of replacement pto shaft parts and pieces. Every part on a pto shaft is replaceable. As long as it is the same shaft shape(walnut, trilobe, square... and category). If they have much damage than yes you can simply replace it as an assembly but keep the old one to steal parts from. Shields and yoke ends get pricy. You can buy a slip clutch for shear bolt conversion to go on the implement end. I did on my land pride cutter a few years back for like $70 dollars. It has been great for me as I probably slip the clutch on every ant hill I find. There are two common types. 1-3/8 smooth or 6 spline.
Based off your sig. you probably need cat 4 drivelines. (I'm sure someone will disagree on the following)If you stay with shear I would run grade 5 bolts, nothing harder. They will give you more use than the grade 2.5, or what the oem's spec. You live and you learn, I was cheap when I bought this cutter initially. Now I wont buy a non slip cutter.
SDT is right on the money with the annual adjustment. Loosen two and turn on pto. Then tighten two. This is after you measure the spring heights on initial setup to your pto hp ratings.

 

[kubotafreak]

I ordered a slip clutch (extension) and plan to mount it permanently on the PTO output on the tractor. My thinking is I will have one clutch to adjust for all of my implements attached thereto.

They usually go on the implement end. Has to do with driveline flex I believe. I believe it provides more protection on the implement end. It also does not act like a cantilever on the pto stub shaft. the pto distance is engineered to a specific depth vs three point arms/drawbar.

 

[GeoHorn]

Behlen is a mfr’r of slip clutches and they state the proper adjustment (compression) to place upon the clutch is achieved by loosening the compression-spring bolts/nuts until the compression-spring can be rotated with your fingers. After spinning it with your tractor-PTO...then tighten the bolts/nuts paying attention to the point the spring cannot be rotated with your fingers... PLUS 1-1/2 additional turns of the bolt/nut. Finished.

(Not certain if everyones’ fingers are calibrated the same as Behlens’ technicians.).

 

[Crash277]

Behlen is a mfr’r of slip clutches and they state the proper adjustment (compression) to place upon the clutch is achieved by loosening the compression-spring bolts/nuts until the compression-spring can be rotated with your fingers. After spinning it with your tractor-PTO...then tighten the bolts/nuts paying attention to the point the spring cannot be rotated with your fingers... PLUS 1-1/2 additional turns of the bolt/nut. Finished.

(Not certain if everyones’ fingers are calibrated the same as Behlens’ technicians.).

thats about as accurate as the carb sync on my 1970 suzuki... there is no measurement.. you use your finger to feel if the slides are at the same height at idle and WOT and adjust as needed..

 

[kubotafreak]

Behlen is a mfr’r of slip clutches and they state the proper adjustment (compression) to place upon the clutch is achieved by loosening the compression-spring bolts/nuts until the compression-spring can be rotated with your fingers. After spinning it with your tractor-PTO...then tighten the bolts/nuts paying attention to the point the spring cannot be rotated with your fingers... PLUS 1-1/2 additional turns of the bolt/nut. Finished.

(Not certain if everyones’ fingers are calibrated the same as Behlens’ technicians.).

I have also seen some give specific spring heights. You will need a set of calipers to measure.

 

[Crash277]

page 28 in the manual for the model I have (RTA1250 50" LT DUTY FWD ROTARY TILLER)

311-883m.pdf (landpride.com)