PTO slip clutch adjustment

[brohloff]

Have had for 15 yrs a 42" Landpride 3 point tiller that I use behind my JD4300.
Came new with a Landpride shear pin pto shaft. Works well. Shear a few pins
every year doing a few garden tillings for the kids.
Son recently bought a nice used JD 4100. Came with a JD 450 tiller and a
Walterschied 82.81.87 pto shaft that has a slip clutch on it.
Going to sell the 450 tiller(going to share the landpride) but thinking
of swapping pto shafts as thinking the slip clutch pto is a better one to have.
Would you agree? Looks like a heavier duty shaft and has a SC.
Second more imp Q.
Cannot find any info on how to check this SC out or how to do a proper
adjustment. Believe it's a friction setup. No ID on clutch itself. Don't
know if it's Walterschied or other. No manual.
See pic's.
In the pic w the 4 bolts, I've backed them off (they were flush w top of stud)
thinking that is how to release the pressure but nothing moves so going to
reflush the 13mm nuts to original.
Did some forum searching. No help.
Any ideas on how to check this SC and do proper adjustment?
Maybe I'll just let this shaft go w the 450 and keep my OEM shear pin
shaft.
Comments?
Sorry for long post?.
ATTACH=CONFIG]370134[/ATTACH]

 

[Blade Breaker]

I understand your thinking. Sometimes the shear bolts can be a pain. If the gearboxes have different HP ratings you may have an issue. If the two tillers have the same HP rating you should be good.
I just bought a tiller that has a slip clutch PTO shaft. This will be the first one of these I have owned. I am curious to see how it holds up. I would be skeptical not knowing the history of the clutch if it has been abused?

 

[Soundguy]

loosen bolts, slip clutch, tighten them till it does not slip in normal operation.. or to a set torque IF you could find the manual

 

[bilrus61]

Is the tiller going to be left to sit outside? If so the shear bolt is a good choice. Everyone says service the slip clutch but its a real pain to do that every spring for 4 or 5 impliments and I think most don't, and there is the "rub". You end up using a rusted together clutch or using one not adjusted right,slips too easy and it burns up unless you keep a sharp eye on it. While its a pain to replace a shear bolt the slip clutch isn't pain free either like many have you believe.

 

[ovrszd]

I agree with all tips so far. As Soundguy said, loosen bolts, engage PTO and slip the clutch, then retighten. This procedure should be done every Spring. Some OCD types even loosen the clutch bolts and leave it stored slack. When you retighten and start adjusting you need to mark the plates and discs with a marker so you know if it's slipping. A clutch that won't slip is pretty much worthless.

In this case, I would disassemble the clutch. Expecting to find junk discs and rusted plates.

Latly, if you've ran a shear bolt for 15 years with no discomfort I'd continue using it. The only way that clutch will last 15 years with no discomfort is if it rusts solid.

 

[Egon]

Do a search here on slip clutches. Lots of threads.

 

[brohloff]

Thanks for the info re shear pin vs SC pto's. Will do a little more digging into this subject.
Still not sure how to check or adjust the SC I have.
Only adjustment is 4 bolts sticking out perpendicular on one side. 13mm nuts tightened
flush with the tops of the bolt studs.
When I loosen the nuts up past the tops of the studs nothing moves back with the nut.
No springs under the nuts as some have. Perhaps the clutch disks are rusted together?
Just not very intuitive how the nuts position effects adjustment or anythingMaybe need
to put on pto and loosen things and then try to twist it to see if it has an effect.
Just have a chance to get back at it.
Appreciate your continued comments……..
b…

 

[greg_g]

Not unusual to have to pry one or more pressure plates away from the friction disc(s). Rust on the pressure plates and shellac on the friction disc negatively impact slip clutch operation. As the service history of the slip clutch drive is apparently unknown, don't get rid of the Landpride shaft until you disassemble/clean internals/reassemble/adjust/test and find the slip clutch operation acceptable. If it can't be done by hand, you're right about the possibility of shocking them free with the PTO

//greg//

 

[SPYDERLK]

Im not sure that clutch is externally adjustable. We need to understand the hidden workings better. Try backing the nuts one turn and if the stud doesnt move in at all then back the nuts enuf to protect the threads. Use an old bolt [inverted] for a punch and give the stud a light blow. Maybe thatll move it and the clutch will slip with pto power.
larry

 

[BukitCase]

Those "bolts" look more like studs to me - and they're too far away from center to be anything but retainers for what appears to be a cover plate.

My slip clutch (6 foot Priefert tiller) has 6 or 8 (don't recall) adjustment springs/nuts, and they are quite a bit more "inboard" than your four. It's open so you can see them easily. BTW, I remove the entire PTO shaft and store it indoors, at least until I get more covered space and can put the entire implements indoors.

Comments on adjustment method sound like what's written in my manual. IIRC, mine tells you to "run a pattern" (like you would when tightening lug nuts) when you're adjusting.

I'd consider taking all 4 nuts and loosening them til there's about half the threads still engaged (just in case) and then seeing if you can get the (what looks like a) cover to move - if that happens with no surprises, I would think you'll find MORE bolts inside that would be your actual adjustments... Steve

 

[brohloff]

All good comments but still no progress on opening or adjusting this SC. Can't see that the nuts do anything as they are 3/16" away from the plate through which they protrude.
That outer plate can only move inward(if it moves at all) as every other side slot has an indented edge acting as a retainer to keep it inside. Viewing through the slots there does
appear to be 2 disk materials or plates but nothing is even pryable…It's solid.
This pto shaft is likely about 12 yrs old and it's possible if it's never been opened or maintained it's all frozen up.
I flushed the nuts back to the studs and rapped on them with a hammer and nothing seems to move - solid. Those are deep 13mm nuts and perhaps that is why the are there. For
rapping to unfreeze (maintain?) the interfaces…… A thought anyway.
Anyway, at this point, unless I have some great revelation, I'm back to keeping the original shear bolt OEM pro shaft…. I "get" how that thing works !!!! Though maybe a SC would be an upgrade.
Back to KISS.

 

[brain55]

There is no adjustment on the clutch. The nuts can be tightened down to compress the Belleville springs so you can bend the housing back out of the way and remove the discs and springs. Once removed you can remove the nuts and disassemble discs and clean off whatever rust or dirt there is and then reassemble in the reverse order. I usually use a pipe wrench adjusted to the right distance to grab the side of the housing and the dimpled in portion and bend it back out far enough to clear the disc assembly.

Brian

 

[greg_g]

Agreed, it probably uses Belleville springs rather than the more common compression coils. Four nuts are sufficient to distribute pressure on a Belleville. Agree as well, that the reason you're at an impasse - even with the nuts loosened - is that the disc and plates are likely frozen. Again, I suggest you mount the tiller, connect the PTO shaft at both ends, keep the nuts loose, and use horsepower to try and break them free

//greg//

 

[bigtiller]

I had a JD 450 tiller for several years, here is how I adjusted the clutch.

Loosen the 4 nuts. Then hand tighten them finger tight. With a deep set socket and short extension, tighten all 4 nuts 1 revolution at a time. Keep track of the number of revolutions and keep all 4 equal. Connect the pto shaft to the tractor and engage the pto {engine OFF) and try to move the tines. When you can't move them any more you are close. Tighten the 4 nuts another revolution.

Write the number down so you can do it again next time a little faster.

Put the tiller in the ground and watch the tiller working, looking for smoke from the clutch. After about 20 feet check the clutch housing for heat. Keep checking it every few minutes.

You may even want to place a 3 ft. 2x4 in the tines to replicate a root or rock to see how slow the clutch slips. You want it to slip just enough to not kill the engine, giving you about 2 seconds to react and shut the pto off when tilling.

If you tighten the nuts too much, you will in effect, lock the clutch tight enough that it won't slip. If you use a second tractor with more or less horse power, you may need to adjust the clutch for it.