More stupid bushhog questions

dannyk · Jul 28, 2003

Sorry if this is repetitive, but every year there are new greenhorn bush hog users (like me) hooking up there hogs for the first time. I figure repetition is good! I just bought a Southern Equipment 4-foot hog to use with my B7500 on about 8 acres of pasture. Bear with me here. /forums/images/graemlins/crazy.gif Here are my questions:

1. The shear bolt is 3-1/2" x 1/2". What grade bolt should I use for replacement? The mechanic who delivered it said grade 5, others say grade 2.

2. To adjust the cutting height, I assume I first adjust the rear height as desired with the bush hog gauge wheel and then adjust the front height with the tractor hydraulic lever so that the mower is level or slightly higher in the rear. The top link I assume is just set so that the hole will match to the hole in the A-frame on the front of the hog when the unit is level. (This A-frame has lock nuts on the bottom so the whole A-frame can flex slightly. There is about 4 inches of chain between the A-frame and the bar which connects to the rear of the mower.) Is there any consensus about replacing the top link with a chain, since the only purpose of the top link would be to lift the mower, and the chain would give more room to flex?

3. I further assume (lots of assumptions here since the mower did not come with any directions or manual!) that I can lift and lower the mower with the PTO spinning.

4. And I assume I should engage the PTO at about 1000 engine rpm instead of 2600 engine rpm (PTO speed) to be easier on the driveline and to avoid breaking shear pins unnecessarily.

5. I'm thinking that when I encounter sedge hillocks or anthills, that the best way to deal with them would be to back up slowly into them in order to avoid hanging up anything on the underside of the tractor. (This tractor doesn't have a great deal of ground clearance anyway, and there will be some mid-mount mower linkage still attached.)

I really appreciate the time it takes to respond and to let me know if I've said anything that is incorrect. I know that many of you veterans spend lots of time answering the same questions over and over. But I also think that it's important, especially given the limitations of the search engine for this site, to keep some of these issues near the front page.

Thanks again,
Danny

Bird · Jul 28, 2003

1. Probably a good idea to follow the manufacturer's recommendation instead of ours or the mechanic's recommendation; however, the mechanic may (at least should) know what the manufacturer recommends. Keep in mind that the grade 2 will shear more easily, so you might have to change it more often. However, that also means it provides more protection for the brush hog and the tractor. I'd use grade 2. /forums/images/graemlins/wink.gif

2. I think you understand how to adjust it. ( Is there any consensus about replacing the top link with a chain. ) I don't think there's a concensus; just some different opinions, and those opinions may vary depending on the type of terrain they have to work with. /forums/images/graemlins/wink.gif Personally, I figure you have enough flex with what you have and I would use the regular top link. However, if you have some really deep ditches or sharp ridges to cross, might want to re-consider. /forums/images/graemlins/wink.gif

3. Yes, you can lift the mower with the PTO engaged and turning; just be sure that the length of the PTO driveshaft is correct; i.e., that lifting it doesn't compress it enough to damage it and you need to do that anyway before the first use.

4. Yes, engage it at idle, then move the throttle up to PTO speed. And personally, I also moved the throttle back to idle and let the brush hog return to the slow speed before disengaging it.

5. Yes, and if necessary raise the mower a bit with the 3-point, back slowly over them, then slowly lower the mower onto them.

6. Oh, you didn't ask a 6th one, did you? /forums/images/graemlins/wink.gif /forums/images/graemlins/laugh.gif

JohnMiller3 · Jul 28, 2003

( a Southern Equipment 4-foot hog to use with my B7500 ) 

Even if the rotary cutter came with a Grade 5 shear bolt... I would use a Grade 2 because of the lower PTO horsepower rating of your tractor...

rambler · Jul 29, 2003

2. If you use just a chain, should you be driving along kinda fast some day, & come across an unseen rock or stump or something, it is possible for the mower to pivot up & land on you (ROPS will stop it if you have one, but that pto is going to be a mangled mess!). While this does not happen every day, and _many_ people go with just a chain, it is a possibility that something bad could happen. The few inches of chain should be enough flex. The top link has a second purpose - to keep the mower down should you bump into something.

3. It's not so good to run the mower while it is up - things can fly out & around.... Most people do, but if you had a manual, it would tell you not to do so for safety reasons. I guess out in an open field, I'd be tempted to do so also. In a yard with other people nearby, I'd think long & hard about the dangers. As someone said, every tractor varies a bit from 'standard' so make sure the pto shaft isn't too long or too short when you _slowly_ move the 3pt through it's full swing. You will not damage the mower or your tractor lifting it while running (unless the pto shaft goes to an extreme angle, some ptos are real high, or the 3pt arms lift very high or are too short...). But consider who or what is around you....

6. I'm not familiar with your tractor, but if it doesn't have live pto, you will want an ORC on the pto shaft. You're probably ok, but for other newbies using older tractors, something to think about. Without live pto, the brush hog will act like a flywheel & keep moving the tractor, even if you push the clutch in.

--->Paul

chrisjbell · Jul 29, 2003

Y'know, the thing is with Bird that by the time you see a post he's already given the correct answers /forums/images/graemlins/laugh.gif.

I'm one of the folks that is scared of using a chain as a top link, but there are others that feel quite differently. But side to side with a hog seems dangerous to me. Yes, call me a wimp - especially when it comes to dealing with dangerous equipment.

But a quick addition... you will almost certainly need to adjust your 3PH height while running as you hit different terrain. You should avoid running the thing with it "up", but should feel free to bump it up and down as needed to accomodate what you're mowing.

dannyk · Jul 29, 2003

Thanks guys. I'm getting the picture. Bird, I DO have a 6th question /forums/images/graemlins/wink.gif Looking at my shear bolt, it says 307A. In browsing the internet, I see that this refers to the grade of the bolt, e.g., http://www.boltscrew.com/inventory.htm. What is a grade 307A bolt?

And one more! /forums/images/graemlins/laugh.gif Since the hog does not cover my rear tire tracks, I assume I can offset the hog slightly to the right or left using the sway bars (with the limitation that my three point hitch doesn't hit my tires). This would allow me to mow a little closer to one side, for example along a fence line.

Thanks again.
Danny

CTyler · Jul 29, 2003

Run a search on your favorite search engine with "grade 307A bolt" you'll find your answer. Its essentially a grade 2.

JerryG · Jul 29, 2003

I use a chain inplace of the third arm. I do it because of the extreme rough that I mow. Before I installed the chain, I bent the third are 2 or three times, going across ditches.
Having said the above and having new members always coming on board, I will ask a question that I have ask before. Has anyone here actually known of anyone that has had a bush hog flip over on them because they used a chain link? Do you know of this with first hand knowledge? (Not from your third cousins second wifes lasts boy friends sister. /forums/images/graemlins/crazy.gif)

Bird · Jul 29, 2003

( What is a grade 307A bolt? )

I'm glad CTyler answered that one 'cause I had no idea. /forums/images/graemlins/laugh.gif

( I assume I can offset the hog )

It can be done; have to adjust the lower links to one side, then have to adjust the height on the adjustable one to get them level because when you swing them to one side, you'll find the side you swung them to is now higher than the other side. I experimented with that a little bit, then went and bought a wider brush hog. /forums/images/graemlins/frown.gif Just 'cause it can be done doesn't mean you're gonna like it, but who knows, you might like it better than I did.

dannyk · Jul 29, 2003

Thanks, CTyler. I had missed the Nucor pdf download.

And Bird, I'll try experimenting with the offset. I don't think that a wider rotary cutter is an option for the B7500.

Danny