Slipclutch question

   / Slipclutch question #1  

Richard

Elite Member
Joined
Apr 6, 2000
Messages
4,813
Location
Knoxville, TN
Tractor
International 1066 Full sized JCB Loader/Backhoe and a John Deere 430 to mow with
We've got a 10' Rhino sitting behind an International. This mower has a slipclutch on the main shafts gear box but none on each side gearbox.

Every now & then if I scalp or hit a stump or.... :rolleyes: the blades will stop as the slipclutch is doing its job.

I turn around and see the main shaft just humming away (pto speed) while the side shafts are revolving slowly or even stopped.... :eek:

I'll raise the deck to clear the grass/scalp/other.... but it takes a moment for the side shafts to spool back up to synch with the main shaft.

My question is.... how long should that process take?

Once you raise the deck, should it be near instant? Having not measured the actual time, it might take 3-5 seconds to go from the worst I've seen it to being synched back with the main shaft.

I've gone though the adjusting process with the main shaft (slipclutch) but having never seen one work other than this, I have no reference point to know if it's re-synching just fine, too fast or too slow (meaning my slip clutch plates might be worn)

thoughts?
 
   / Slipclutch question #2  
How many HP is the tractor? If under about 80 the slip clutch on a 10' should stall the tractor without even getting hot -- that would mean pretty quick. Your clutch is adjusted far too loose. Tighten it a lot. Then scalp heavily. If the clutch doesnt warm as the engine lugs down loosen it til it warms a little as the engine bogs down quickly from full rpm to 2/3rpm. That is the very loosest the clutch should be. Otherwise you will burn it up quickly because it will slip often and excessively. BTW, you should disengage pto if the mower gearbox has stopped. 540rpm input 0rpm output=burnt clutch almost immediately.
larry
 
   / Slipclutch question #3  
I agree with Larry. It should be in the "very short" to "very very short" time, so you do have to tighten it up like Larry says.

I know the slip clutch is working when I smell it burning slightly. It's how I got quick reflexes on the PTO lift and engage levers!
 
   / Slipclutch question #4  
BUsh Hog rep tells me slip clutch should almost instantly quit slipping on ANY application if sized correctly and adjusted correctly. shafts should return to full speed as soon as resistance that caused slipping has passed. Long story short, IMHO, your clutch is WAY too loose.
 
   / Slipclutch question #5  
If it has "slipped" very often you may need to replace the discs. While it sounds like yours is way too loose, don't crank it down to where it can't slip at all. After it has set for an extended period of time(like all winter outside) Rhino recommends loosening off the bolts and letting it slip some and retightening to get the rust off of the plates. You sure don't want one to be locked up solid. Gears, yokes and U-joints can get expensive.:(
 
   / Slipclutch question
  • Thread Starter
#6  
How many HP is the tractor? If under about 80 the slip clutch on a 10' should stall the tractor without even getting hot -- that would mean pretty quick. Your clutch is adjusted far too loose. Tighten it a lot. Then scalp heavily. If the clutch doesnt warm as the engine lugs down loosen it til it warms a little as the engine bogs down quickly from full rpm to 2/3rpm. That is the very loosest the clutch should be. Otherwise you will burn it up quickly because it will slip often and excessively. BTW, you should disengage pto if the mower gearbox has stopped. 540rpm input 0rpm output=burnt clutch almost immediately.
larry

International 886. I think it's about 80 hp though I'm not sure (non turbo if that were to matter)


hmm.... your last comment 540 rpm input, 0 rpm output = burnt clutch almost immediately....

If that's really accurate then these plates were probably already toast when we got the mower.
 
   / Slipclutch question
  • Thread Starter
#7  
I'll go tinker with them & see if I can tighten them.

My guess based on the last time I put the power train together is, they're fairly loose (when hitting something) and as I recall, the height of the compression springs was where it was supposed to be.

Since the consensus seems to agree that the plates are adjusted way too loose (or perhaps already smoked)...let me ask this....

as long as I'm staying in normal stuff to cut...or even tall stuff... Just this morning, I cut a small field with waist high 'stuff' that hadn't been cut in probably 12 months. I scalped a couple times and during that, the blades stopped. While I was cutting the field itself, I think the blades only slowed down once as I hit a real dense area of growth (I was also in 4th gear purring along so I was feeding it fairly quickly)

Anyways.... as long as the mower cuts in 90% of my mowing applications, is there a risk/danger in having the plates too lose other than annoyance?

Can it be unsafe?

I realize that if/when they might get too lose in an absolute sense then perhaps a toothpick will make them slip BUT, if I can cut an entire field and only have it slip on me once/twice.... is it worth paying "X" dollars to buy new parts or just keep on slipping on?
 
   / Slipclutch question #8  
I'll go tinker with them & see if I can tighten them.

Anyways.... as long as the mower cuts in 90% of my mowing applications, is there a risk/danger in having the plates too lose other than annoyance?

Can it be unsafe?

I realize that if/when they might get too lose in an absolute sense then perhaps a toothpick will make them slip BUT, if I can cut an entire field and only have it slip on me once/twice.... is it worth paying "X" dollars to buy new parts or just keep on slipping on?
Tighten them up several turns -- 2 or 3 each - - right away and then be sure it can slip as I described. Even a burnt clutch can work. The reason you should not go on as you are is that the clutch is slipping more often than you know - just not enuf so the blades stop. In cutting grass thick enuf to stall your tractor the clutch should not slip. Its when you hit a cinderblock, stump, big rock, or scalp very abruptly that a slip should occur. This should range from a split second in the case of passing over a stump or cinderblock, to as much as about 2 seconds while the tractor stalls if the blades get snarled in chicken wire or a chain or heavy scalp. Note that a 2 sec slip to stall is only about 10 turns. Even a burnt clutch can work if its not destroyed. You must tighten yours or it will be.

No you are not likely in any danger.
larry
 
   / Slipclutch question #9  
Danger? not to your person. Maybe to your wallet. If you keep slipping, it will keep getting hot and may warp. It could (how likely, dunno) then need to be replaced. That would be a lot more than just some 20 buck discs.

jb
 
   / Slipclutch question #10  
Look to see if you can determine a brand name (manufacturer) of the slip clutch. (NOT the mower, but the slip clutch itself) In most cases, proper setting of tension is achieved by measuring a static "stack height" of the springs. Some brands are even "tune-able" to various hp ratings by setting different stack heights. (Measurement of spring in compression) Possible brands are Comer, Eurocardan (sp), ect. Also look for a model #. Post that info. Possibly someone with simular item can give more specific advice.
 
 
 
Top