So, what's slipping?

[rd_macgregor]

I was running my Wallenstein BX62 chipper on a DK45SC at just over 2000rpm last night and managed to jamb the chipper. The chipper and PTO shaft stopped going around, and the tractor bogged down a bit, but didn't stop until I shut it down.
I had to head back to the house to clear the jamb because I didn't have a wrench, but everything seemed to turn OK after clearing the chipper.

So, my question is, what was slipping? Since the PTO and chipper both turn just fine, I obviously didn't shear a bolt, which implies something inside the tractor was slipping. I hope somebody with a better understanding of the mechanics of tractors (which is just about anybody!) can reassure me that this is normal and not likely a problem.
Thanks,
BOB

 

[somguyss]

What you did was slip the hydraulic clutch pacs internal of the transmission. Your tractor is equipped with an electric over hydraulic circuit, this being said when you turn on your pto by the switch it energizes a solenoid that always fluid thru a block to pressurize a clutch pac to lock up the shafts. When your tractor is running imagine your shaft n the transmission is a 2 piece shaft with a clutch coupling the 2 together. When there is no pressure on the clutch pac hydraulically they operate as 2 but when hydraulic pressure is applied it locks the 2 up to become 1 and give you your output. It is scary that your slip clutch didn't slip properly or that your shear bolt didn't shear. The last thing that should have happened was to slip the internal clutch pac, if it slips to bad it can rip the linings off the individual discs in the clutch pac and cause premature slipping or even failure. So word of advice is check your shear bolt for proper grade, and or if you are running a slip clutch instead it needs to be set up properly either by you or the dealer. If you are running a slip clutch if they sit up for long periods of time they will seize to one another and be like having a straight shaft. Which in turn can cause damage internal to the tractor and possible personal body injury.
So I advise to having those things checked and good luck.

 

[rd_macgregor]

I suspected something like that. The chipper is essentially brand new (I bought it in May but first used it last week); the shear bolt is the factory one. I suppose it is always possible that the Wallenstein follks installed incorrect bolts, so I'll check the grade. I'd sure rather replace shear bolts than pay to have my tractor torn apart for repairs!
Thanks,
BOB

 

[Coyote machine]

I don't know if they make an item like I'm going to suggest, (assuming it exists), which could be installed between your PTO shaft output and your chipper input shaft to possibly prevent excess strain on your tractor's trans when the chipper's shear bolt fails to shear. I would say consider an add-on slipjoint coupler attached to the PTO output to function as described above. Someone here will know, if such a beast exists.
If one is available I would consider it if the chipper is totally dependent on a shear pin to save your tractor's trans.
I say this from personal experience on a Dr. Brush machine where the snow blower attachment destroyed my trans, and left the shear bolt intact. It was all brand new, just like your chipper. Dr. covered it and replaced the trans free. I received a credit for purchase price on the snow blower and never looked back.
If your chipper were to destroy your trans, I for one bet you would have to pay to fix your tractor, unfortunately.

 

[rd_macgregor]

I managed to jam it again this weekend and it did shear the bolt this time. A slip clutch is a great idea, but requires some vigilance to be sure the plates don't rust themselves together leaving NO protection (as happened to a poster on another thread with a slip-clutched bush hog behind his DK45).
Having read about the slip-clutch issue over the years, I think all drivelines with slip clutches should also have shear pins. If you start to shear pins, that means your slip clutch isn't operating/adjusted correctly. It would be great to have some other backup to protect the tractor transmission.

BOB