Rotary Cutter Bush Hog gone bad

sandman2234 · Oct 2, 2006

This post is to try to determine what might have gone wrong, what could be damaged, what is damaged, and is the whole thing worth fixing, or should it be donated to the pile of scrap that China is killing us with?
Here is a series of pictures taken after dark in order to try to determine if the bush hog is fixable. I told the owner that anything was fixable, but some things were not worth the trouble and expense they would take to fix. Sometimes it is just better to bite the bullet and buy another one instead of trying to fix some things.
I am posting these pictures that he sent me, in hopes that some of you will pick the pictures apart, finding every flaw with this bush hog, and maybe offer some guidance as to what it would take to fix it and what to look for in cases of things that might be damaged that don't show up in pictures.
Without further tado, here are a couple of pictures, and the rest in links, so as not to slow the loading too far...
David from jax

http://img.photobucket.com/albums/v177/sandman2234/tractors/jb8.jpg

http://img.photobucket.com/albums/v177/sandman2234/tractors/jb1.jpg
http://img.photobucket.com/albums/v177/sandman2234/tractors/jb4.jpg
http://img.photobucket.com/albums/v177/sandman2234/tractors/jb5.jpg
http://img.photobucket.com/albums/v177/sandman2234/tractors/jb6.jpg
http://img.photobucket.com/albums/v177/sandman2234/tractors/jb7.jpg

MrJimi · Oct 2, 2006

Dave, you know, I'm new at this but I would say something serious got stuck under it. Looks like cast iron? I hope its not. You have the pieces, weld it.
Jim

sandman2234 · Oct 2, 2006

My first thoughts are, ok, going to be some work, but it is fixable. I was originally told that the gearbox casting was broken, which would mean more money usually, but this isn't as bad,(my opinon) but will require more work.
I see a gearbox that has to come off, and the deck mount rewelded, and then reinforced using a piece large enough to cover a good size part of that upper deck, to keep the damage from reoccurring. My thoughts were that two of the bolts worked themselves loose, allowing the gearbox to move as the blades pounded small trees and other semi non-moveable items. This movement caused the deck to crack, and the crack spread unchecked until the piece actually fell out and somebody took notice.
The leaking seal on the input shaft could just be from drying out and wearing out, or it could be from the bearing right behind it going bad and allowing the shaft to destroy the seal. Best ways to determine that, might be to remove the pto shaft and check the side to side/up and down movement of the shaft to see if there is any play in it. If there is no excessive play, put a new seal in and the gearbox is ok. Might want to consider putting the lower seal in at the same time, while you have the gearbox off...
This particular style of gearbox is pretty common and can be purchased off ebay for less than $50. In fact, there is a good chance I have one, but the seal is bad also, if memory serves me right. Won't cost near as much to ship mine north, as to buy one off ebay, but that is yet to be determined as the need of it.
What do the rest of you think about it?
David from jax

RonR · Oct 2, 2006

Well, I'll take a shot at it. I had trouble seeing any details in the followon pics.

Before I spent any time/effort to fix it, I'd free up the PTO drive and roll it over by hand a lot to see if I could feel any roughness in the gearbox. If there is roughness, I might not go any further, unless I planned to replace the gearbox.

That damage was either fatigue (doubtful) or stress of impact. Anything that stopped the gearbox with enough force to break that out HAD to put some stress on the gears. If it just recently happened, you can look at the edges of the broken metal to see if its all fresh or not.

The broken out part could be easily beveled and then welded back in. If I were doing the repair, I'd do that, then overlay the plate to the front and rear to give it some new structure to hold it.

I'd also check to see if the blades run true (the output shaft or bar under there might be bent from the impact).

The weld fix doesn't look tough, and worst case, you could refill the gearbox with heavy oil and run it till it comes apart again.

ron

sandman2234 · Oct 2, 2006

I tried to pick the best pictures of the bunch to show first. The rest were more for id of the gearbox, and overall condition of the bush hog, from my point of view.
I pretty much agree with what you guys are saying. Seems we are thinking along the same lines, and were probably all typing at the same time.
Does anyone see anything else wrong with the bush hog that would negate spending the time and effort on this welding repair, just to run into another problem that will add to the amount it costs to repair?

For the record, I won't likely be doing any of the repairs, just trying to help out someone who could use a little help. The bush hog is a couple of states away from me, or I would just volunteer to give it a shot at repairs.
David from jax

schmism · Oct 2, 2006

so am i missing something.... why is that section of the hog cast?

why not just cut out the whole (week) cast section and replace it with a piece of 8 or 10 C (steel).... in the structural world that size is used for all kinds of stuff...

else braise it... (cast doesnt weld worth a crap)

JerryG · Oct 3, 2006

Sandman,
I would defiantly fix it if it were mine. There is more than one way to go about a fix like that. What I would do is to bevel all edges of the section that is broken. Weld it back in on the top and bottom, then grind the top part smooth. Cut a section of channel that is about 18” long to fit down to the flat part of the deck and also cut it to fit around the gear box flange. Then weld the sectioned channel to the deck. While you’re at it check the other gearboxes mounting holes for cracks.

firemanpat2910 · Oct 3, 2006

If the gear box is any good just put a big steel plate under it and bolt it back in. Then pull the shear pin and make sure its not rusted together,and replace with a proper grade shear bolt,or slip clutch. Also check pto shaft for twisting or other damage. then check the angle and length of pto when hooked on tractor. also check to see if sway chains are properly set. trying to determine what happened this time is tough so you want to cover all likely problem areas. Is there any oil in the gear box? After looking at pic 1 again that was cracked for a while before it broke,look at the different levels of rusting, and the extra crack running to the left. Are there spider web cracks around the other 2 bolt holes?

Soundguy · Oct 3, 2006

I may be wrong.. but that looks like an old crack on the right, the metal is rusty. This may have been old stress cracks due to loose bolts, and then it finally went.

Also.. it may be cast steel and not cast iron. If cast steel.. welding will be a breeze.

I'd deffinately weld it up, and brace / gusset where needed. Check for more breaks.. checkt he gear box.. etc.

Soundguy