Breaking Bush Hog Shear Bolts - Shaft

jdraper · Feb 26, 2007

After spending weeks reviewing tractors, I bought a new 5740C basd on many of the discussions here. Overall, I am happy with one great exception. I connected my Woods 6' Hog to it...set the PTO to Manual, set the engine RPM to IDLE and slowly released the clutch in my attempt to feather in the PTO as I have done with other tractors... Even though the RPM's were VERY low, the driveshaft on the Woods twisted in two! The clutch will not allow me to feather at all, it is all in or nothing with the implement PTO. I dropped in a new shaft and new shear bolt (just in case the hardness of the old bolt was too high). I have since sheared off three more bolts using the same technique. It does not happen every time, but verty frequently. My dealer acts like he has no idea what is going on, and suggested I use the Independent setting to engage the PTO (flick the switch and engage the PTO without regard for the clutch position). I did this at engine idle and did not break a bolt the first time I did it, but have not had a chance to cut since then. Yes, the gear box has oil... and I can splin the drive shaft freely by hand, it is not in any sort of bind.

Does anyone have any ideas? Can you feather the clutch to slowly engage the PTO on a Montana tractor? What is the recommended PRO engagement method?

Thanks...

Maka · Feb 26, 2007

What grade bolt?

Maka

Doc_Bob · Feb 26, 2007

The tractor is not the problem.
Bob

ToddW · Feb 26, 2007

I broke some shear bolts this weekend bush hogging but it wasn't the tractors fault, clearly the operator.

What grade are you using now? My Woods HSS60 specs out a 3" long 1/2 NC Grade 2.

/Todd

TillerofdaEarth · Feb 27, 2007

Can you feather the clutch to slowly engage the PTO on a Montana tractor?

The answer is no!

When you select manual, all you are doing ,is changing the PTO engagement control to a micro-switch on the clutch pedal. So, as you are lettting out on the clutch, no matter how slowly, as soon as the micro-switch makes....BAMB! The electic PTO clutch engages just the same as if you selected the independant PTO position.

Check to make sure, as Maka asked, that you have the correct gade shear bolts installed. Another option would be to install a slip clutch drive on the mower PTO.

montanaman · Feb 27, 2007

TillerofdaEarth said:
Can you feather the clutch to slowly engage the PTO on a Montana tractor?

The answer is no!

When you select manual, all you are doing ,is changing the PTO engagement control to a micro-switch on the clutch pedal. So, as you are lettting out on the clutch, no matter how slowly, as soon as the micro-switch makes....BAMB! The electic PTO clutch engages just the same as if you selected the independant PTO position.

Check to make sure, as Maka asked, that you have the correct gade shear bolts installed. Another option would be to install a slip clutch drive on the mower PTO.

Exactly as stated. I think you were thinking that the tractor has a two stage clutch but the PTO is completely independent on your tractor. If you select to use the clutch option, it just goes through another switch before the power goes to the PTO.

Just my thought but you have a pretty big tractor to be running a shear bolt protected cutter behind. I'm not knocking the shear bolt units and I use one myself but they usually are not the high end units and have lighter driveline parts and gear boxes. You can add a slip clutch to the cutter you have or buy the type that bolts to the PTO shaft and has the 1 3/8" six spline male for your cutter but you may need to shorten your drive shaft.

Ken

loukas · Feb 27, 2007

Try this: If your tractor has a loader curl the bucket back all the way till the hydrualics deadhead. This puts the pump in bypass, at this time engage the pto. There will be less preasure at the pto clutch. Sounds crazy but it works good.

Big_Charlie · Feb 28, 2007

Ask your dealer to come out and adjust the PTO engagement solenoid. I had this problem the very day my R4944HST was delivered. They can adjust down the strength with which the PTO is engaged by turning a screw located under the right rear fender somewhere. I haven't had a lot of opportunities to use the PTO since, but the few times I have, I haven't had a single problem.

Maka · Mar 1, 2007

Hi BigCharlie. Be careful and make sure the dealer does not adjust to much or when you run an implement and start getting in heavy stuff you can start slipping it and then possibly cause damage.

Maka