PT425 48" Brush Hog Broken Bolt Removal Tip

[PTWannaHave]

Since I am not familiar with the issue, the following is an observation more than a suggestion...

If I understand the problem correctly, hex bolt heads get severely damaged or sheared off by hitting something hard at high velocity. The rest of the bolt remains in the welded nut, and can be very difficult to remove. (This is a royal PITA.)

I have a blades for my mower that look like a bush hog setup. Basically, short blades that are free to swivel, attached at one end to the edge of a disc. (Four blades per disc.)

These blades are attached with a Button Head bolt (a.k.a. Round Head). These bolts usually have a hex drive or Torx drive hole in the head. Using such a bolt greatly minimizes 'catching' the ground, as the dome has a much better chance/tendency to 'float over' obstacles.

1/2-20 BUTTON HEAD SOCKET CAP SCREW, Each - Palmer Bolt & Supply Co.

Cheers,

 

[woodlandfarms]

we have reviewed the button head idea on my end and in the end I walked away. I might revisit. Reason for walking away is that the hex portion tends to get bent up, not allowing a hex key to fit in to loosen and remove the blade without substantial work. Now, this is just theory and conjecture but it might take a long time to file the opening on the bolt to get a hex back in. But in its defense I have only once taken a blade off, and that was when a spindle was having an issue. Otherwise I just wait for them to break away.

Second, I am not sold it is only the head that is an issue. while the cutting edge provides a ramp of sorts, the end is blunt, i have broken on small stumps, and y tought was that the blad gets wacked back and on the next time around its blunt end stikes the object.... Theory again.. Probably the blade is staightened out within a half turn of the rotor...

But you know what, why not, right? Next time I am in Woodland I will pick up a bag and give them a try if they make them in our size.

Carl

 

[MossRoad]

How are "regular" brush hog blades attached on "regular" tractors? Do they have the same breakage issues?

 

[MossRoad]

O.K. So here's the real problem as I see it. EVERY brush hog that I can find on the internet has GULL-WING BLADES!!! Meaning, the blades have a bend in them so that when the blade comes around after hitting an object it cannot shear off it's partner's bolt!!!

AND, the center drum on EVERY brush hog I can find on the internet is a LOT SHORTER than the PT design, which allows for the dip in the blade. If you tried to put gull-wing blades on a PT brush hog, you would gouge the ground pretty good, even with the wheelsl set on the highest setting.

Someone (Power Trac, are you listening?) needs to come up with a retrofit kit that makes the drum shorter by an inch and a half so that we can put gull-wing style blades under it and resolve this terrible design/saftey issue.

There, I feel all better now and will stop using CAPS in my post.

 

[cqaigy2]

hmmm i may just have to try those out.

 

[BobRip]

Could you change the wheel brackets so the mower could be raised higher or would that allow the blades to be too exposed?

 

[MossRoad]

Could you change the wheel brackets so the mower could be raised higher or would that allow the blades to be too exposed?

Yeah, I think it would expose the blades too much. It needs a shorter drum. The current one is HUGE. I could probably cut two inches off of it and shorten the shaft, then put on the better blade style. Hmmmm..... DANG! Got me thinking again of projects I don't have time to complete!!!! :mur:

:laughing:

 

[MossRoad]

Had to replace a blade again today. I knocked it off in the spring and now its firewood season, so had to put it back on so I can clear my logging trails. The two jam nuts on the backside did the trick nicely again to get the broken 2.5" bolt out after the head snapped off.

I made my own spacers that go inside the blade holes out of DOM tubing that I bought from On Line Metals last year. That saved quite a few dollars, as I can probably get 20 or more spacers out of a 12" piece.

Order Mild Steel A513 Tube in Small Quantities at OnlineMetals.com

Still haven't had the time to investigate retrofitting a "normal" brush cutter head and blades to the underside of the PT deck. I've been looking at bush hog brand decks, and this parts diagram in particular, for ideas. Sounds like a winter project.
http://www.bushhog.com/uploads/documents/BHRotaryCuttersq36-sq84oldPM-03.pdf

 

[woodlandfarms]

Moss, on your PT how do you reach these nuts? Do you have to drop the Spindle?

I am not sure if I reported this but last year I cut a bunch of holes in my deck (3 to be exact plus 3 drain holes) These holes allow me to use a rig I made (A nut welded onto a long bolt with just a bit of thread hanging out). I rotate the spindel so that the broken bolt is visible through the hole in the deck. I then thread the long bolt with welded nut onto the existing nut. Slap on my impact wrench and down it goes. I then lif the mower and grab on with vice grips and spin the broken bolt out. Right now I am averaging around 5 or 6 broken bolts a year (I am continuing to push back the blackberries and brush and there is always something noisy and sparky and fun to hit buried within). I have to get a metal detector.

Oh, as for spacers on my machine I am just using 3/4" black pipe. Seems to work fine for my system.

 

[MossRoad]

Yeah, I've read about those holes you drilled. Sounds interesting. I just take an air impact wrench and a crescent wrench and remove the two hydraulic motor bolts and get that out of the way. The upper lovejoy section stays on the motor shaft. Then I loosen the allen screw on the lower lovejoy section. Then the impact wrench on the 5 lug bolts and the whole spindle drops to the ground. I stand between the two front wheels, grab the caster arms, do my best Bill Kazmaier impersonation, and lift the deck up and walk it backwards to get it over the spindle.

That whole process only takes about 5 minutes. Then I just back the broken bolts out the rear with those jam nuts and a crescent wrench.

To put it back on again, I just to it in reverse order. If all goes well and I have all the parts, its 15-20 minutes.

I'd rather convert it to a design where the blades can't whack each other's mounting bolts and be done with it.

I have to wonder, though, about blade length. The PT design has long blades and a narrower center drum. The bush hogs I've been looking at have short blades with wider center drums. The blades are gull winged and since they are also short, they can't hit the other blade or blade bolts. But I wonder if the shorter blades have the knock down power of the longer PT blades? I'd hate to convert it only to realize I can't destroy brush as well as the PT does now.

This time I did put in 2.5" bolts with long spacers in the spare holes on the drum. I'm hoping I can sacrifice those and they'll stop the blade from hitting it's partner's mounting bolt. They look to be down a bit lower than the blade bolt heads. I'm guessing they'll hit some rocks or stumps before the blade mounting bolts and I'll hear it and back off before the damage is done. I'll give it a test later this week or weekend and see how it goes.