How to properly adjust King Kutter II slip clutch

   / How to properly adjust King Kutter II slip clutch #1  
S

seapea

Gold Member
Joined
Apr 29, 2005
Messages
274
Location
SF Bay
Tractor
Kubtoa B2620
How do you know if you've properly adjusted the slip clutch for 48" King Kutter II. The directions say to tighten 1.5 turns, but "further adjustments may be necessary". This is done after first losening the nuts and then hand tightening them until they make contact. However, it took 3 or 4 turns to get them loosened, so either they were way to tight to start with, or I'm not tightening them enough. How do I tell if it is too loose or too tight?

I put the tiller to use for the first time for about 20 minutes today on some very hard (and not very moist) clay. For the most part there were no problems, but I had to go very slow. Once in a while the engine would start to bog down a bit, and lose 100 to 200 rpm. I just let up on the pedeal and it corrected right away. Is this normal?

BTW, I have a Kubota B2620, which is 26hp, 19 at the PTO.

Thanks!
 
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   / How to properly adjust King Kutter II slip clutch #2  
Seapea,

For the clutch, it's exactly as the manual says. Loosen all 8 bolts on the clutch until the springs are "free" (from the factory, it is set WAAAYYY TOO TIGHT), make sure the clutch slips, then tighten all 8 nuts by hand until the nuts push the springs up against the flange. Then tighten then 1 1/2 turns more. This is the starting point.

Now, Go try your tiller. If it doesn't slip in the ground you're tilling, then you're done. If it does slip without hitting any objects, then tighten all 8 bolts a little more, I'd say 1/2 turn at a time. Try it again. If it still slips, then another 1/2 turn... you get the picture. Also, although the manual doesn't say it, be sure to let the clutch cool down completely after it slips and you adjust it tighter, before you try it again. It will get hot very quickly if it slips.

What you're trying to do is set the clutch so that it will transmit just enough torque to operate the tiller in all the normal soil conditions you will encounter, but no more than that... that way if you hit a hard obstruction like a brick or rock or an old truck axle, when the tines hit, the clutch will slip, and prevent damage to the tiller.

You have a 48" tiller, so I'm guessing that the initial setting on the clutch will be just fine. I've got the 72" KK tiller, and the initial setting worked fine in the "old" part of my garden, but I tilled up some virgin sod on one side to make the garden a little larger, and the clutch began to slip about 6-8 feet into the first pass in the sod. So, I did the procedure that I described above. I ended up going an extra turn (for a total of 2 1/2 turns after the springs were on the flange) on all of the nuts before the clutch wouldn't slip while tilling the sod.

Like I said, if your clutch does slip, be sure to let it cool before trying again... It may slip easier when it's hot than when it's cool, and if you adjust it to where it won't slip when it's hot, it may be set too tight for when the clutch is cold, and you could possibly damage the tiller if you were to hit something later on.

That sounds normal for what you were seeing with your rpms... a tiller is a pretty good load for your tractor, and it will make it work harder than most implements. 100 to 200 rpm is nothing to worry about... as long as you can increase your throttle (not the hydrostat ground speed) and the engine will accelerate under load, you're not pulling the tractor too hard. What you don't want to do is something like be at full throttle and bog the engine down to like 1500 rpm or less... that's overloading it. But, these engines are tough... you'd have to really really abuse them for a long time before you'd do any damage, so don't be afraid to let that tractor work... that's what they're made for.
 
   / How to properly adjust King Kutter II slip clutch
  • Thread Starter
#3  
Hi Brian,

Thanks for all the info. Just one more question. How do you know if it is slipping? Does the tiller stop spinning, or is it possible for the tiller to spin while some slipping is going on? If the later, I'm not sure how you can tell if this is happening.

thanks,

Chris
 
   / How to properly adjust King Kutter II slip clutch #4  
The the tines will just stop spinning. It may be possible for the clutch to slip a bit and keep the tines turning, but I believe it's more of an "all or nothing" situation... once it slips, the compound in the friction discs in the clutch require that everything comes to a relative stop or the load be removed before they will grab again... and like I said, it will likely have to cool down as well before you'll be able to keep going. That's the way mine acted when I was getting it set. Once it slipped, it was done until it cooled off.

You can also make a few passes, and and then go back and feel the clutch; if the clutch is still cool, then it's not slipping. They get hot FAST when they slip, so you have to keep an eye on what's going on, because if a slipping clutch goes unnoticed, you could burn up the friction discs.
 
   / How to properly adjust King Kutter II slip clutch #5  
KK has used several brands of slip clutches on their tillers over the years. You need to know which brand you have. (Eurocardan, Comer, ect) Each brand has a specific adjustment. So far as I know, ALL of them are PROPERLY adjusted by tightening the springs to a specific compressed height.
 
   / How to properly adjust King Kutter II slip clutch #6  
seapea said:
How do you know if it is slipping?
Click to expand...
A loud squealing noise is usually the first indication. It's typically loud enough to get you to turn around in your seat, at which point the smoke coming off the friction plates should be obvious.

Losing a few hundred rpms isn't unusual, and serves to prove that the clutch is not YET slipping. But if you lose too MANY rpms without slippage, the springs are too tight. Like FWJ says, there's more than one type - so there's more than one adjustment procedure. My Eurocardan manual for example, has a spring length chart that is linked to PTO horsepower. I found 40hp on the chart, got a caliper, adjusted the hex nuts until all 8 springs equaled the specified length.

These clutches stick over time, recommended maintenance includes loosen/clean/tighten at least once a year.

//greg//
 
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   / How to properly adjust King Kutter II slip clutch #7  
GREAT advice from everyone, I wish I had been on this board when I bought my first one
 
   / How to properly adjust King Kutter II slip clutch #8  
greg_g,

Hey, is there any chance you could post that Eurocardan chart? That's the shaft that came with my tiller, and probably the majority of the others also, but the KK manual doesn't list anything like that. I still think the method that I posted is what KK wants you to use, but the chart would be interesting. I definitely wouldn't set the slip clutch according to a chart though, at least not without some guidance from the tiller manufacturer, whoever it is, this isn't necessarily limited to KK. I'll explain why in a bit.

FWJ... You're right that there's several different brands that KK used over the years, but I don't think that's what KK wants you to do... at least according to their "procedure" (and I use that term pretty loosely:eek:). You're right, when we KNOW how much HP or torque we need to transfer... but in the case of our tillers, we really don't know this number. We've got an idea, but, no hard numbers.

For example, let's say that Seapea, or any of us for that matter, had greg_g's chart, and we decided to set the slip clutch to transfer up to 35hp (just for the sake of discussion) because we have a 40hp tractor (again, just for sake of discussion). Also, since we know that the tiller has gearboxes rated for at least 50 hp (because we know that they use the same gearboxes on all of the models, and the 72" is rated for up to 50hp) so we assume that setting the clutch for 35HP gives us at least a 5HP cushion, so everything will be OK.

Now we're tilling along with our 48" tiller on our 40 HP tractor, with the slip clutch set to transfer 35HP. Everything's going great until we hear a big bang underneath the tiller, and the tines stop rotating and the clutch slips. We think everything's OK, because we have set our slip clutch correctly according to the chart, right? But, we go back to see what we hit back there, and find that buried truck axle again. We also see that 1 tine is twisted back like a pretzel. HOW COULD THAT HAPPEN? Here's how:

In reality, it was only taking about 14 hp (an arbitrary, but realistic number) to drive the tiller in our hardest soil conditions. If we have that slip clutch set to transfer 35hp, then that one tine that caught the truck axle had to transfer 21 extra horsepower to that truck axle all by itself before the clutch would slip. So, in essence, that one tine had to transfer nearly double the amount of power that it was actually taking to drive the tiller, and it was just too much for it to withstand, and it yielded. Time to buy a new tine. Did the slip clutch do it's job? Well, it slipped at the torque level it was "set" for, but it was just set too tight, and we damaged the tiller. So, in effect, no. Not through fault of the clutch, but operator error.

That's why I think that the way the KK manual "leads" you to do it (and the way that I posted) is correct. You only want to transfer the amount of torque necessary to get through your toughest obstacle-free areas, and not much more than that at all. That way when you hit that truck axle or whatever else lurks in the depths of our gardens, food plots, etc. ;), there's much less risk of damaging anything. The only real problem I have with it, is that we don't know how much more torque we're setting the clutch for by making, let's say, 1/2 turns on the nuts, since that's what I advised. But, that's what I did on mine.

If we arbitrarily set the clutch off of a chart, without any guidance, then we're getting into "shear bolt" territory, without the shear bolt. Which is fine, if the manufacturer gives some guidance about where to set the clutch for the particular tiller model... but unfortunately, they don't. They leave it up to us to figure it out on our own. You could certainly set the clutch for a lower HP number, but that's just a guess too, and if it slips without hitting anything, in reality, what are you going to do? I believe that the way I posted earlier is the proper way to do it, as long as you make small adjustments, and make sure that the slip clutch has completely cooled after it has slipped. And, it works for pretty much any brand of slip clutch that KK may have used.
 
   / How to properly adjust King Kutter II slip clutch #10  
Cool, thanks! Just have to make sure that that chart is for the slip clutch that we're talking about here...
 
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