Slip clutch

[john_bud]

As per another thread i posted i have a question. I bought a NEW shredder and i can easily turn the blades under neath until they 'stop' then pull them by hand, which i assume is the clutch slipping. Th emanual made no mention of tightening the clutch down before use. Ive used it for 20 hours now like this with no issues.

Whats the deal, is this bad, or not?

Unless you wear a long blue suit with a red cape, I don't think you are slipping the clutch.

You may be turning the internal over riding clutch in the tractor. Unless you have an old non-live PTO tractor, there is a clutch that allows the PTO to spin and not the transmission. Old tractors without live PTO had a solid connection between the transmission and the PTO shaft. Meshed gears. Now, imagine you are using a cutter and you come up to a dead end and need to turn around. You put in the clutch, but the inertia from the rotating cutter is still spinning the transmission - forcing you forward into a tree, ditch, house, road etc. The ONLY ways to stop was to slip the trans into N and coast around the corner or slip the PTO out, other wise the implement powered the tractor. Scary, but that's how they made them back in the day.

You do need to verify the slip clutch is slipping once a month. More often if you see rust forming.

jb

 

[Soundguy]

Or he could be pulling them backwards.. and there is an ORC in the setup somewhere ??

Soundguy

I didn't see your other thread, so maybe I'm missing something here. But given your opening description, perhaps it's the whole shaft your're turning - simply because the PTO up on the tractor is disengaged. With the PTO lever in neutral (and the tractor not running) it's quite easy to reach under the deck and rotate the blades - whether the cutter is equipped with a slip clutch or not.

When you're moving the blades by hand - and get to the point where you think you're slipping the clutch - can you observe the PTO shaft turning all the way back to the tractor? Or do the blades continue to move after the PTO shaft ceases to rotate?

//greg//

 

[agford4x4]

I don't know, i looked last night and turned it, it appeared as though the shaft on the tractor was NOT turning. The springs on teh clutch are tight to spec at any rate, and i know its not slipping because i use the **** out of it and it cuts anything it goes over.

 

[1bush2hog]

Since there are different types, can you post a picture of your slip clutch?

The slip clutch on my cutter has 8 bolts that you have to loosen, make sure the clutch plates are loose, and then retighten to specs provided. Your slip clutch is made to slip at a certain level of resistance depending on your setup.

The slip clutch specs will change after you use your machine for awhile, so recheck the specs according to manual recommendations. There is no way I can check whether or not my slip clutch is slipping with my hands. If adjusted to loose the blades will stop rotating in thick grass - if too tight... I hope I never find that one out

 

[agford4x4]

It has 8 bolts, 1 1/16" spring length.

It doesnt stop in high grass or brush, so its probably ok. Maybe the whole shaft actually does turn, but with the tractor off and the shredder attached to the PTO, I can pull or push the blades for completel revolutions underneath. Like i said, its torqued to spec, and it seems to work fine, so i believe its probably ok.

 

[JerryG]

If it's not, you won't find out until it is to late and things are broke.

It has 8 bolts, 1 1/16" spring length.

It doesnt stop in high grass or brush, so its probably ok. Maybe the whole shaft actually does turn, but with the tractor off and the shredder attached to the PTO, I can pull or push the blades for completel revolutions underneath. Like i said, its torqued to spec, and it seems to work fine, so i believe its probably ok.

 

[bucmeister]

If when you say "shredder" are you meaning a brush cutter such as a "bush hog" or is your shredder something that may have belts. If it is a brush cutter then it may well be that there is slippage or an over running clutch type mechanism, if it has belts then as you turn the blades backwards you will unload the spring idler and the pulley will slip on the belt like my Wood's RM-990 does.

As far as how tight to set the clutches, I like mine to be just tight enough to let me do the normal job at a normal pace, if I am in heavy brush cutting down saplings I want those clutches to slip a bit every now and then, I can pick the "hog" up and let it catch back up or slow my ground speed down a bit and it gets to slipping to often then I just put a wrench on the bolts and get another 1 or 2 flats worth of tight on each one and go some more. I figure the slip plates are a lot less costly than any thing else that would "give" when it is in a bind. But, that is just my weird way of handling it.

 

[agford4x4]

Well, there really isnt a lot to a rotary cutter. I mean, its torqued, the grass, weeds and brush are getting cut, it doesnt make noise, the clutch isn't hot, etc. I have no reason whatsoever to be concerned with it at this point. There is 8 bolts and springs on it that are all torques to spec, so i doubt there is any issue with that, its not likely it is defective. Quite honestly, i would be more concerned if i couldnt force it to turn or slip. It has a warranty, i should know soon enough if its a problem i would think. Ill pull off the driveshaft gaurd and see if i can determine if the whole pto shaft is spinning or if its actually slipping. I think its actually slipping, but maybe not.

 

[flusher]

Well, there really isnt a lot to a rotary cutter. I mean, its torqued, the grass, weeds and brush are getting cut, it doesnt make noise, the clutch isn't hot, etc. I have no reason whatsoever to be concerned with it at this point. There is 8 bolts and springs on it that are all torques to spec, so i doubt there is any issue with that, its not likely it is defective. Quite honestly, i would be more concerned if i couldnt force it to turn or slip. It has a warranty, i should know soon enough if its a problem i would think.

Don't know what kind of tractor you have (note: fill out your profile), but I can turn the PTO shaft by hand on my Kubota B7510HST when it's parked and the pto lever is in neutral. Like you, I can turn the cutter blade by hand when the tractor is parked and the transmission is in neutral. The entire PTO shaft, including the slip clutch, turns when I do this.

There's no way I could cause a properly adjusted slip clutch to slip by turning it by hand.

 

[JerryG]

This will almost assuredly be my last post on this thread.
Having said that, I’m sorry but you just don't get it. I don‘t mean that is any rude way at all, but this is something that has to be done or it will cause damage unless a person is very, very luck.
If it is too tight OR if the plates and discs are stuck and you hit something solid such as a half buried rock or a stub of a stump or even if you just scalp the top of a ridge of dirt too hard there is a very high probability of something getting broke. Your warranty will not cover it, because the manual warns you about the clutch and the need to re-set it up periodically. It doesn't make any difference whether or not that it was or has ever been torqued to spec or not. If or I should say WHEN they stick and they will stick, there will be a very good change of damage. It is bad enough to bust a u-joint or twist a PTO shaft, but when the gears in the tractor are damaged, the cost is a lot higher. Now, if the dealer set it in the last month or so and actually did it right and the humidity hasn’t been too high, you may be alright for a short period.
I have seen too many PTO shafts and far too many transmissions damaged because of the owner not taking care of their PTO clutches. I don’t know but if I was still in the business, I really think that I would only sell shear pin equipped brush mowers. That is unless an experienced owner wanted one.

Well, there really isnt a lot to a rotary cutter. I mean, its torqued, the grass, weeds and brush are getting cut, it doesnt make noise, the clutch isn't hot, etc. I have no reason whatsoever to be concerned with it at this point. There is 8 bolts and springs on it that are all torques to spec, so i doubt there is any issue with that, its not likely it is defective. Quite honestly, i would be more concerned if i couldnt force it to turn or slip. It has a warranty, i should know soon enough if its a problem i would think. Ill pull off the driveshaft gaurd and see if i can determine if the whole pto shaft is spinning or if its actually slipping. I think its actually slipping, but maybe not.