Rotary Cutter Slip clutch not slipping at factory specs...

[North Country]

If it's brand new, it may still have the factory varnish coating on it. You're supposed to slip them when new and every season, so I'm guessing yours is frozen pretty tight now.

 

[SPYDERLK]

Bush Hog model 285.... EG/Comer slip clutch...

It isn't slipping at all. Never slipped since new and it's probably a couple years old. I loosened all the bolts on the clutch, turned the driveline by hand and the gearbox didn't turn, which tells me that it isn't froze up.

Re-tightened all the bolts to factory spec (1.26" / 32mm spring length) and it still isn't slipping! Killed the tractor 3 times the other day and I'm scared something's gonna break if I don't get it to slip.

This is my first and only implement I have that has a slip clutch.

What should I do? How many turns do I need to back off of each nut?

Thanks.

Your slip clutch should stall the tractor fairly quickly when there is an extreme overload, but should slip a little while doing it. It is for catastrophic overloads like big rocks or stumps or such. If youre just cutting thick brush it should not slip at all. If youre cutting along and hit something that stalls your engine in about a second that clutch should slip. Jump off and feel it - it should have some heat. If not, loosen the springs a little at a time until that type circumstance does cause some heat.
larry

 

[slowzuki]

I'll add my baler has a slip clutch because the huge flywheel on it would stall the tractor, it slips a tiny bit when you kick on the pto. Some big bushhogs are like this too, the rotating mass is really high.

 

[Travis_R]

I still haven't got it fixed yet, but I have been working on it. Looks like im gonna have to loosen all the nuts to where there're just barely on there and engage the PTO and let it slip for a few seconds... I'm at my wit's end! :mur:

 

[Chilly807]

Land Pride recommends loosening the bolts 2 turns, then engaging the PTO to slip the clutch. With mine I think I'll loosen it about a turn and a half and see what happens with normal mowing. If it gets warm I'll tighten another half turn.

There's a length measurement in the manual for the springs, mine's already looser than that and no signs of slippage.

They are, as spyderlk said, meant to prevent sudden shock, not to allow the clutch to slip when simply overloaded.

Sean

 

[JoelD]

Sounds like your plates are frozen together with rust

Pullnit apart and clean it up

 

[SPYDERLK]

Sounds like your plates are frozen together with rust

Pullnit apart and clean it up

Note that Travis R indicated he had loosened all spring tension and the clutch spun freely.
larry

 

[Chilly807]

According to the manual for mine, the spring length is supposed to be 1.000" to 1.010" when operating. Mine was set at 1.080 when I got the mower new.

This morning I backed them off another half turn, which made the spring length 1.115". After mowing a bit, I noticed the discs had moved maybe 45 degrees in relation to each other, probably on startup or slowdown, but the clutch was still cool to the touch. I may try loosening them a little more, although I think I'm where I want to be anyway.

Sean

 

[JRobyn]

Also have a BushHog brand model 286. I DID contact Bushhog about the correct spring length to use for a Kubota L4330, w/something like 38 PTO HP. The 286 gearbox is rated for 110 hp, so my concern was that their "standard" clutch setting was way too high and could result in tractor damage if left set there. Their reply? (I quote) - "The gearbox is rated for 110 hp but regardless of the tractor all cutters should be set at 1 3/32."

I ignored them and set it like Ken said.

 

[Chilly807]

Also have a BushHog brand model 286. I DID contact Bushhog about the correct spring length to use for a Kubota L4330, w/something like 38 PTO HP. The 286 gearbox is rated for 110 hp, so my concern was that their "standard" clutch setting was way too high and could result in tractor damage if left set there. Their reply? (I quote) - "The gearbox is rated for 110 hp but regardless of the tractor all cutters should be set at 1 3/32."

I ignored them and set it like Ken said.

Nice standard "company policy" answer, isn't it..

I'm willing to bet the setting protects their gearbox from overtorque from the tractor, but the tractor end of things (read expensive) is YOUR responsibility.

Largely, the days of a company willing to take a little time to look after their customers personal needs are gone.

Sean