Another brush hog mower question

[JerryG]

Sounds like there is to much slop in the hole and also in the splines. Are the splines on the shaft and on the hub worn so bad that they are slipping? If that is the case, you may have to drill the hole for a larger bolt if you want to fix it enough to get by. I bet that at one time the owner put too small of a bolt in.

 

[JimR]

Ah Ha, Maybe that is the problem. I did cut down a lot of trees and wrapped quite a few right around the mower blades so bad that the blades stopped spinning. Maybe the bolts are bending and cauing them to snap off. I'll try that the next time one breaks.

 

[GEB]

Not that I know much, but what about your tractors HP compared to the bush hog?
I think my 47hp tractor is over rated for my 40hp BH.
So far so good for me, but are ya over powering the BH?
Gene

 

[JimR]

My Cub has only 27HP. I know that is not the problem.

 

[SPYDERLK]

Farmwithjunk, I can understand where you are coming from. These folks are the same way.

Here's the picture of the lower shaft. There is 1/2" of play up and down at the ends of the blades. The mower attachment is rocking on the output shaft a bit. There is no back and forth slop in the splines. I used it for another hour today and that 5/16" bolts is still in there. I think the smaller bolt may be the answer.

If its rocking on the spline shaft it may be too late to save it. Id try a loctite retaining compound to fill the gap and hold it still. High strength #638,green, weakens with reasonable heat so yould be able to get it off if you set up a threaded hole in the hub center to use a push bolt.
Larry

 

[sandman2234]

They don't want to sell the farm equipment they have. They prefer to just let it sit out in the field and rust away. It is really a shame as they have a couple of old tractors and haying/agriculture equipment just rusting away. I salvaged the brush hog and hope to swap it out for my labor to do their fields.

In that case, good luck with the repairs, and be careful with YOUR new mowing deck. Clearing old fields can be rough on them!
David from jax

 

[sandman2234]

This is probably going to show some of my ignorance as a tractor owner/operator, but what the heck, here goes.
A bush hog, to me is a awesome thing that takes out small trees and leaves a nice grassy patch in it's place (given a little time for fresh growth)
A RM, rotary mower, is a rough cut lawn mower, capable of chewing up and spitting out acres and acres of heavy grass day in and day out.
I would not consider a bush hog a bush hog unless it has a stump jumper, since any small tree can slip past the blade and get slammed against the fixed bar, which has no option but to stop which shears the pin.
I think I would install either a round disc or a stump jumper on that baby, as well as to return to the correct size shear pin.
David from jax

let the flames begin...

 

[JimR]

This is probably going to show some of my ignorance as a tractor owner/operator, but what the heck, here goes.
A bush hog, to me is a awesome thing that takes out small trees and leaves a nice grassy patch in it's place (given a little time for fresh growth)
A RM, rotary mower, is a rough cut lawn mower, capable of chewing up and spitting out acres and acres of heavy grass day in and day out.
I would not consider a bush hog a bush hog unless it has a stump jumper, since any small tree can slip past the blade and get slammed against the fixed bar, which has no option but to stop which shears the pin.
I think I would install either a round disc or a stump jumper on that baby, as well as to return to the correct size shear pin.
David from jax

let the flames begin...

I can honestly say that from my experience over this past week that what you say is true. This mower cuts woods brush and small trees fine except for the occasion jam up because it doesn't have the stump-jumper on it. In heavy grass it bogs down badly. If you drive slower it can cut heavy grass, it is however, very time consuming. Every tool made has its place. I think I may be pushing this one to its limit. At least the fields are done and my old neighbors are tickled pink about it. They said it hasn't been like that in over 10 years. That bolt I keep mentioning is not a shear pin. It is there to only keep the assembly on the shaft. The shaft and mower blade assembly are splined. I'm going to look at this assembly a little more and see if I can move the blade all the way up to tighten it up. Maybe pushing it up, turning the locating and drilling a new hole may solve the problem and looseness. I'll also check to see if there is a bolt hole in the end of the shaft. There is a hole in the center of the blade assembly.

 

[sandman2234]

OK, but let me caution you about something. Drilling a splined shaft, or any other round shaft for that matter isn't as easy as it seems. You might consider locating someone with a milling machine and the expertise to do it correctly. There are plenty of Bridgeports owners in your neck of the woods, that can do it. Drilling it with a drill press is possible, but if you drill thru it and it comes out even 1% to high or too low, you can't fix it with a drill press.
Since it will require removal of the gearbox to do it, how about taking pictures of the entire unit, and measurement of the bolt patterns. Somebody might just have an old gearbox that will bolt right on, for less money than fixing the old one. (Assuming the splined shaft is worn?)
Is it possible that the play is coming from the blade carrier and not the spline shaft? It would seem the shaft would be harder than the blade carrier, although both would have to be somewhat soft in order to be machined with a spline. Just a chance that the gearbox shaft was hardened when the gear on the end of it was heat treated.
Enough guessing,
David from jax

 

[JimR]

Dave,

I ws thinking of drilling the removable part, not the shaft. I would imagine the shaft is heat treated. More than likely it was done after the splines were put in it. I would think that the blade carrier is the part that is worn. I'm going to pull it this afternoon and measure the splined shaft on the gearbox to see if it is worn.