Bush hog drive shaft/pto question

[slydog]

I just traded a case of Coors light for this old bush hog. I haven't had any experience with a bush hog since a teen in high school, and I need some info about a couple of things, and would greatly appreciate any help anyone has to offer. I know the blades need sharpening, as the leading edges look to be about as sharp as a 1/4 dowel. In other words, totally rounded over and a little rusted. The gearbox turns the blades very smoothly by hand, with no forward/backward play at all, and no stiffness or grinding. I am pulling this behind a 1955 Ford 640. The fellow I got it from advised me to use case hardened bolts in the drive shaft hole connecting the shaft to the gearbox spline to prevent them from shearing so often, so I bought about 10 bolts to use for this. However, a fellow at work advised me to use regular bolts, as I want the bolt to shear to prevent any damage to my PTO drive. What is correct here? I don't want to be changing bolts out every 5 minutes, but I don't want to tear up my tractor or bush hog either. Also, the top links of the 3 pt hitch, have been cut and section of chain welded in (i'll post a pic showing this in a followup post). Should I change this out to solid top bars or leave the chain in? Previous owner said this allows the bush hog to ride up and down slighty over ridges. Any thoughts??? Also, let me say that I have only recently found this site, and I think it is one of the best sites around regarding rural living!!! And it is great to have such a valuable source of information and expertise! Thanks in advance,
Ken Ellis
Southaven, Ms and future resident of Greers Ferry Arkansas.
<font color="black"> </font>

 

[slydog]

Picture of the chains which were added to top links of bush hog.

 

[BB_TX]

You don't want to use case hardened bolts for your shear pins. The shear pins are there for a reason, and that is to protect your tractor PTO drive. Buy shear pins from your tractor supply or use #2 grade bolts. I run a 6' rotary cutter and have only sheared 2 bolts in over 4 years. And that includes cutting some pretty heavy brush and hitting some pretty substantial deadfall and other junk washed up out of the creek.
As far as the chain, some people prefer a chain to a regular top link. That gives it more latitude to move up and down over uneven ground. Some concern has been expressed about hitting a stump or other object and the mower deck flipping up and over. I think that is very unlikely unless you have a LOT of HP and a LOT of traction.

 

[Bird]

Ken, as has been said, I'd use grade 2 bolts; much rather have to replace one of them than damage the tractor and/or mower. As for the chains, in 1995 I bought a new Bush Hog squealer that came originally with chain instead of the solid bars; don't know why they changed, but if it were me, I'd just leave the chains alone.

 

[beenthere]

I'll chime in and support keeping the chains. I just converted mine to chains and now don't have the steel straps bending when the rear of the deck comes up (like when backing into an up-hill slope). Watch that the chains don't entangle in the un-covered PTO shaft (is it missing or just off for the pictures?).

Also, I support the shift back to shear bolts, not hardened ones. Hopefully the previous owner hasn't already damaged the cutter's gear box. Otherwise, if too many busted shear pins, look into a PTO clutch (maybe two cases of beer if you get the right person /forums/images/graemlins/grin.gif )

 

[bczoom]

slydog,

Welcome to TBN.

You've gotten good advise from BB_TX, Bird and beenthere. These guys are always dead-on.
When the seller told you they were breaking off often, did you ask how often? What kind of terrain was he running it in and what are you going to be running this thing in? I'd be concerned if I was shearing a bolt every 5 minutes.

BTW - Good trade.

 

[slydog]

<font color="blue">Watch that the chains don't entangle in the un-covered PTO shaft (is it missing or just off for the pictures?).
</font>

<font color="black">There is no cover. As a matter of fact, there is no cover on the PTO at the tractor either. Maybe I should get one. </font>

<font color="blue">When the seller told you they were breaking off often, did you ask how often? What kind of terrain was he running it in and what are you going to be running this thing in? </font>

<font color="black">Well..I really didn't ask how often. But since the blades are so dull, and considering the fact that he told me "that thing will cut anything that my tractor will push over", and since his tractor is about twice the size of mine, I just figured he was working the hell out of the bush hog. The terrain I will be running it in is some gently sloped, at times uneven terrain. I am sure there are a few hidden rocks about the size of bowling balls that I will have to find. That was one reason I wanted an old bush hog instead of a new one. I doubt that I will be shearing a bolt every 5 minutes myself, as I plan on locating most of the rocks through careful mowing and looking. I'm just concerned about the ones that "sneak" up on me!

BTW, thanks guys for all the replys. You've been a great help, and it's not always easy to find good information here locally. </font>

 

[Ronbo]

If you have a FEL, mow with it lowered to within 6 inches of the ground. This will locate any large rocks and rims that may be hiding.

I also changed from solid bars to chains about 4 years ago. No problems. I hog about 6 inches high and have run over tires before. No problems.

Ron

 

[slydog]

FEL ?? Front End Loader?? I would love to have one. Does anyone make one that will work with my '55 Ford 640 ?

 

[ThistleKop]

<font color="blue">"I am sure there are a few hidden rocks about the size of bowling balls that I will find". </font>

Slydog, I would wait until I found and removed some of the large rocks before sharpening the blades. Many years ago, I had an engineer tell me that if you sling a two by four fast enough it will cut grass. That may be a stretch but you can get a pretty good high cut with dull blades.

TK