Class III boomer owners BEWARE!!

[jlong]

Soon after purchasing my 35D, I did about 10 hours of Brushogging with a 5' brushhog. Soon after, my tractor was in the shop with a PTO BRAKE failure. Luckily, the tractor was under warranty, as the repair would have been well over $1,000.00.

After talking to a NH rep very knowledgeable about the specifics of the 35D, he stated that with the Class III boomers, he would highly recommend using a PTO over-ride, if the brushog did not have an override. It seems that the force of the momentum of the brushog is far too much for the PTO brake to handle.

I just wish someone would have told me that before it broke. My previous Ford 1520 had no PTO brake, and I am told that they are only on the Class III Boomers. Hope this stops someone else from learning the hard way!!

 

[Bird]

Jim Long (hmmm. . ., I have a brother-in-law in West Virginia named Jim Long and you obviously ain't the same guy). I was just wondering whether you engaged (and especially disengaged) the PTO with the engine running at PTO speed. If you're running the mower at high RPM and then disengage the PTO, I would think that would result in considerable stress and wear on the PTO brake, but if you pull the throttle back to idle and let the engine slow the blades on the mower first before disengaging the PTO, wouldn't there be a great deal less wear and chance of breaking the brake?

 

[markie61]

Hey, jlong! Thanks for the 'Heads Up.'

I remember seeing posts related to the PTO brake failure while I was researching tractors last fall. As a result, I brought it up with the dealer. He said that shear pins, belts, or slip clutches on rotary implements should release before the PTO brake. He also said it's best to engage implements at low RPMs and then evenly rev up to 540 and the opposite when you are ready to disengage.

I have yet to use the PTO on my TC40D, so I can honestly say I don't know if the theory applies in the real world. Do you think engaging and disengaging the PTO in this manner would help the potential problem? Also, did you add a PTO overide and, if so, how much $?

BTW, since I bought my TC slightly used (31hour) and the PTO was never used, I made the dealer test and dyno it before delivery acceptance. It tested out at 38hp, which is almost 4hp more than the spec sheet says. I wonder about the difference. Maybe the test doesn't measure the power loss from drivetrain movement while powering the PTO. Nevertheless, I thought it good information for non-traveling implements, such as backhoes, chippers, PHDs, etc.

Mark

 

[tc35dforme]

I freely admit to being an idiot !!!

Now with that out of the way....does an overunning clutch allow the pto shaft ( tractor ) to stop and let the implement free wheel, or does it let the implement stop ( hitting stump ) and allow the pto shaft ( tractor ) to stay spinning ???

It seems you need to let the implement spin free to save the PTO brake.

Okay ... please educate me ???

 

[Bird]

<font color=blue>allow the pto shaft ( tractor ) to stop and let the implement free wheel</font color=blue>

Yep, it's a racheting device that does just that.

 

[tc35dforme]

Thanks Bird !!!!

One more ? if I could....Are there any drawbacks with their use ??? Wouldn't it make sense to have one on all the time to protect the PTO driveline ???

 

[Bird]

Drawbacks to their use? I don't know of any serious drawbacks unless you consider the cost ($70 to $90 on the ones I've seen). Of course, if you wanted to throttle back, without disengaging the PTO, in order to let your engine slow the blades on the brush hog, that won't work with the overrunning clutch. The brush hog would continue to freewheel. I think those clutches were probably invented for, and first used on, the old tractors that had the PTO geared directly through the differential, so that even if you stepped on the clutch (disengaged the PTO), the centrifigal force (or momentum?) of the blades turning on the brush hog continued to turn the PTO which continued to push the tractor forward and you couldn't stop it. While I've never personally seen it, I've heard stories of tractors and operators being pushed through fences, over embankments, etc. My own tractors didn't have a PTO brake so I never had a need for an overrunning clutch, but there are definitely circumstances in which they would be good to have.

As far as having one all the time to protect the driveline, I don't know how it would protect anything other than the PTO brake unless you have one of the old tractors I was talking about above.

 

[Soundguy]

I have an 8n and it does exactly as you say.. the impliment will power the tractors drive train via the pto with the clutch pressed.. and the brakes on our old tractors aren't the greatest.. in fact.. they are just barely adequate.

Soundguy

 

[yellowdog]

I was told that on an "Independent PTO" such as with the 35D that you did not need to run an override clutch. But after using my 45D for the first time, I assumed it had some kind of brake to stop the PTO when disengaged, and considered this could wear out. So instead of an override clutch I just disengage my PTO very slowly while listening to the bushog. You will reach a point where it disengages without using the brake, and the bushog will freewheel to a stop, then you can fully disengage the PTO (brake applied).