Slip clutch Maintenance Question

[N1ST]

Hi All,

My KK tiller manual says to loosen the SC bolts and let is slip for 2 revolutions. They seem pretty specific about this, so I'd like to do it right. So, when my PTO turns at some 9 times a second, how do I let the clutch slip for for 2 revolutions. I understand the 9 revs/second is when the engine is up to speed, but at idle, will it really only turn once or twice per second?

 

[patrick_g]

Although, I at first misread your handle for NIST (National Institute of Standards and Technology) instead of N1ST, let me say that this isn't rocket science and 3 revs would not hurt a thing.

Secondly, do they direct you to do this with the engine running? I'll bet not. Loosen the bolts and jam either the PTO drive shaft or blades and rotate the other manually. If it is hard to turn, turn the other end to take advantage of the gear reduction. The idea is to make sure the clutch isn't rusted, seized, stuck, or otherwise prevented from relieving the torque. When parked for a long time a slip clutch may bind up and need to be freed up to let it work properly and prevent damage to the more delicate parts of the implement.

This is not a 720 degree +/- 0.0001 degree specification. Just make sure the clutch is free to slip if the torque builds up too much, like when you hit a big rock.

You probably don't use a micrometer when you check the oil with a dipstick and this too is not a demanding "measurement."

By the way, your idle is likely at least 700RPM or more which is probably going to give you a PTO speed of about 130RPM +/- or 2 per second but trying this with the motor running is a VERY BAD idea and can get you nominated for a Darwin award.

Pat (N6AYR, looks tech but is General, originally N5DBP in 1962, DeciBell Pat)

 

[N1ST]

Thanks Pat. It didn't dawn on me that I could turn the shaft by hand, so I assumed that the procedure should be motor driven. Boy, glad I asked! I'll give it a try.

 

[DK35vince]

This is how I slip/check the clutch on my KK tiller.
With engine shut off I back off the slip clutch bolts (my clutch is set where I want it so I count the # of turns so I can retighten them to the same place).
Sit on tractor and start engine, engage PTO, jam tiller into dirt forcing the slip clutch to slip for a few seconds.
Shut down engine an retighten slip clutch bolts the same # of turns.
Tiller is ready to use.
Safe and it takes me 5 minutes or less.

 

[bjcsc]

That's how I do my tiller, too (except I don't count turns, I measure spring length). On my BushHog, I lower the stump jumper onto a 2' piece of 6x6 and then loosen the spring nuts until the springs are loose. I mark the inside plates with a silver sharpie, engage the PTO and let it slip for a good five seconds (clean everything off). I check to see that marks don't line up (make sure it slipped) then I tighten the springs back up to spec length with calipers. I do this at the beginning of each season.

 

[Deadman]

I plan on just loosening the bolts and then engaging and disengaging the PTO a few times at half rpm. That should slip my totary cutter clutch some.

 

[N1ST]

Well, I got around to doing this... just loosened all the nuts, and twisted it by hand. It moved freely. By the way, very impressed with the KK tiller so far. Chopped up the sod to near-potting soil consistently in 1 (slow) pass. Very nice. The outer hub took about 1 tube of greese. For a while I thought it might be filling the axle!

 

[patrick_g]

The outer hub took about 1 tube of greese. For a while I thought it might be filling the axle!

Sounds familiar... Mine is an Italian import (not red, sexy, and doesn't have a convertible top) but when I lubed it I thought I might be filling the axle tube at first. I guess it wouldn't have mattered except for using up quite a grease supply.

Pat