Friction torque limiter and slip clutch adjustment.

[daRedbone]

How tight do I adjust the nuts on the clutch? Thanks.

 

[SPYDERLK]

These compress springs ... right? You adjust to length of the spring rather than tightness. You need a ballpark starting point based on the implement and tractor. What do you have? Any instructions on the clutch?

 

[daRedbone]

50 h.p. tractor driving a 5 ft. tiller. It does compress springs. The instructions in the operating manual are useless. It says to hand tighten nuts until they touch yoke and then 1.5 turns more. The nuts don't touch yoke flange. They are against the spring and it would take a gorilla to hand tighten that far.

 

[Mendonsy]

Ahhh ...... you gotta love those Chinese instruction manuals!!
Is the slip clutch going to be where you can get at it once you are done??
Here's what I would do ....
1) Run the nuts up finger tight against the springs then tighten them 1.5 turns more.
2) Try the tiller to see where you are (most likely not tight enough)
3) Tighten each nut another 1/2 turn and try it again.
4) Repeat step 3 until you get a setting you like.

 

[CobyRupert]

Put a mark on the each of the slip pads, or otherwise take note of where they are in relation to each other before you try it so you can see if it has slipped.

 

[90cummins]

A very important step was omitted here!
Any new clutch must be broken before putting it into service.
The clutches may have oil on them or be stuck because of rust which will prevent it from protecting the driveline.
If there is oil on it they may slip slightly appearing to work but as the oil dissipates thru use the friction can increase preventing the clutch from slipping when an overload is encountered.
The same with a clutch that has set outside it may be stuck due to corrosion.
The procedure for putting a clutch protected implement into service should be to loosen the spring tension to allow the clutch to slip then engage the pto and operate it until the clutch starts to smoke.
This burns off any assembly lube or corrosion.
After the clutch has cooled tighten the spring tension slowly & equally until the clutch will operate the attachment without excessive slippage & heat.
Marking the clutch is one way to observe any slippage another way is to stop the machine after working it hard and feeling how hot it is.
If it is cold then you should loosen the tension slightly if hot more tension is needed.
90cummins

 

[travlitt]

After initial adjustment is accomplished, I set the springs with a feeler gauge. This will give equal pressure on all of the springs.

 

[daRedbone]

Ahhh ...... you gotta love those Chinese instruction manuals!!
Is the slip clutch going to be where you can get at it once you are done??
Here's what I would do ....
1) Run the nuts up finger tight against the springs then tighten them 1.5 turns more.
2) Try the tiller to see where you are (most likely not tight enough)
3) Tighten each nut another 1/2 turn and try it again.
4) Repeat step 3 until you get a setting you like.

Yeah ... I'll let it go at that.
1) I suspected this is what they meant but I've seen spring length adjustment suggestions. Nothing specific to my equipment though.
3) Good plan. I wasn't certain as to how sensative this is.

I hadn't thought about marking the discs. Good idea.

I have no idea as to how I've gotten by for almost 50 years on tractors and never had one of these before.

 

[daRedbone]

A very important step was omitted here!
Any new clutch must be broken before putting it into service.
The clutches may have oil on them or be stuck because of rust which will prevent it from protecting the driveline.
If there is oil on it they may slip slightly appearing to work but as the oil dissipates thru use the friction can increase preventing the clutch from slipping when an overload is encountered.
The same with a clutch that has set outside it may be stuck due to corrosion.
The procedure for putting a clutch protected implement into service should be to loosen the spring tension to allow the clutch to slip then engage the pto and operate it until the clutch starts to smoke.
This burns off any assembly lube or corrosion.
After the clutch has cooled tighten the spring tension slowly & equally until the clutch will operate the attachment without excessive slippage & heat.
Marking the clutch is one way to observe any slippage another way is to stop the machine after working it hard and feeling how hot it is.
If it is cold then you should loosen the tension slightly if hot more tension is needed.
90cummins

All of this is new to me. This one is new from factory so I assumed.... It slips a bit too easy to my liking so I thought a simple adjustment would do. I'll do this first. Thanks.

 

[JRobyn]

My Bushhog-supplied slip clutch and its manual recommend setting by spring length. I once asked their tech support folks what their setting was based on. I assumed it was from their 80hp gear box rating so I was worried about it transmitting too much torque to be safe for my 40ish HP tractor and PTO. They insisted that the recommended length setting was the right setting. Didn't ever really explain WHAT the setting was based on. I suspect their tech support folks really didn't know.

A method of increasing it one small step at a time until it just doesn't, or only rarely slips, is the best IMHO. Once you arrive at a good setting, you can use one of these to easily reset each of the springs to the same place.



As previously noted, it is really important to loosen and intentionally slip it once at the beginning of each season to break the plates free from being stuck by rust. If you store the clutch indoors, this might not be necessary.