Rear Finish Mower John Deere 506 Brush Hog

[lwoomer]

I had some issues with my JD 506 brush hog this weekend. Once attached to the tractor, I kept shearing bolts that contact the PTO to the gear box. I shear about 5 bolts before giving up. I looked under the mower to see any obstructions, but everything appeared clear.

Does any one have ideas as to why I'm shearing bolts right and left? The cheat grass is in need of cutting and my significant other is pretty unhappy about the lack of progress!

Regards, Spring Hollow Tractor Man

 

[thatguy]

be deduction - if there are no obstruction I think it has to be in the gear box.. did you check to see if the gear box has oil in it? I am assuming that the PTO work with other equipment though..

brian

 

[lwoomer]

Brian,

The gear box does have oil and the PTO does work on other implements. I was thinking that maybe I need to engage the PTO at a lower rpm initially and maybe that would resolve my bolts shearing issue. What do you think?

 

[beenthere]

That might be it...what rpm are you engaging the PTO?
What tractor are you using?

 

[RoyJackson]

Brian,

The gear box does have oil and the PTO does work on other implements. I was thinking that maybe I need to engage the PTO at a lower rpm initially and maybe that would resolve my bolts shearing issue. What do you think?

I engage my cutter at about 1500 RPM...just keep your foot near the throttle if you need to "blip" it (if the tractors starts to stall). You may need a little lower or a little higher RPM. Once it's running, give it a few seconds for the blades to pivot out. Don't be surprised if there is considerable vibration initially.
If that solves the problem...great! If it shears pins during operation, you may have something binding up the blades or spindles (underneath the cutter).

 

[rktman]

I use an old 5 footer than shears bolts bad if not treated nicely. The yoke is simply wore out but I can still use it provided that I engage it below 1000 rpm and build up engine speed. Another key is to not to back up. The cost to rebuild the yoke and shaft would probably be more than it's worth. If yours is doing it all of a sudden, I would check your gear oil, u joints, etc.

 

[lwoomer]

Thanks to everyone for the advice. I will hook up the mower this weekend and see if adjusting the PTO RPMs when engaging the mower will work.

Best Regards

 

[beenthere]

That might be it...what rpm are you engaging the PTO?
What tractor are you using?

Didn't want to answer these questions? :confused3:

It is ok, but would be helpful to know.

 

[lwoomer]

Sorry, I have a Kubota L3400 4WD HDT tractor and I've been starting the mower at PTO around 1500 RPMs in the past with no problems. So this situation is unique and that's why it's a little wierd from previous performance.

 

[204saskman]

I had a problem like this with a old finish mower, it turned out being that i was engaging it to high of rpm(1500). I then idled it down to around 900-1000 and it made the difference. I just worked my rpm back up to around 2200 and all was good after.

 

[doall]

not only engage at slower speed, also slowly engage the pto lever. the blades banging together will sheer the pin worse than any small trees.

 

[mjncad]

I engage at idle with the cutter slightly raised up, then slowly bring the throttle up to proper RPM's after the blades have deployed and the initial vibration has gone away.

Whenever I sheared a bolt, it seems related to making a tight turn without raising the cutter up a bit.