Bush Hog BH25 yokes breaking

[Smokeydog]

My similar BH brand, 286 uses round bars. Storing over the winter has my usual grapples on the FEL resting on them bending them down. Still haven’t broke in 25 years of abuse on rough ground and woods. The flex top hitch allows for articulation in dips and backing over trees. I use a solid top link.

Your break looks like a crack then break. Faulty flat bar stock? Surprised by a major manufacturer. Counterfeit and sub standard materials in our supply chain is a real problem. From the other broken bars you have enough materials to make substantial repairs. Letting your dealer and BH know might be remedy too.

 

[Boatman62]

Can we get more pictures of the setup? How the top link attaches?
In my opinion I'd say 1 breaks it is a manufacturing issue.
3 break in one season and it is more likely to be a set up or use issue. Unless the 3 came from the same batch, manufacturer, etc.

I's take them to an experienced welding/machine shop and see what they say the cause of the break is.
To snap a bar like that is highly unusual.

Also, were those bars replaced and where did they come from? Was the first break an original one?
Looking at a picture of the BH25 the bar looks to be angled where it bolts at the rear and not straight like his appear to be.

View attachment 720636

I can get more pics next time I go over in a day or so.

Where your arrow is pointed is where they are breaking and there is about a 15-20° in the bar.

All that have broken are OEM Bush Hog.

 

[Boatman62]

My similar BH brand, 286 uses round bars. Storing over the winter has my usual grapples on the FEL resting on them bending them down. Still haven’t broke in 25 years of abuse on rough ground and woods. The flex top hitch allows for articulation in dips and backing over trees. I use a solid top link.

Your break looks like a crack then break. Faulty flat bar stock? Surprised by a major manufacturer. Counterfeit and sub standard materials in our supply chain is a real problem. From the other broken bars you have enough materials to make substantial repairs. Letting your dealer and BH know might be remedy too.

As I said above. He has talked to both the dealer and directly to BH. No love from either one.

Looks to me the stick the bars are made from is hardened to some extent and when the bend is stamped its ctacking/shearing the steel.

 

[wirlybird]

I can get more pics next time I go over in a day or so.

Where your arrow is pointed is where they are breaking and there is about a 15-20° in the bar.

All that have broken are OEM Bush Hog.

Ok, good to know they at least look correct.
I'm not sure why they would be "hardened" I would think it might make them more brittle.
Looking at where the break is and trying to compare to the picture it looks like the "bend" is further back or closer the mounting point in the picture I found.
May not be, hard to tell!

The only real force on those bars would be -
1: when lifting the brush hog but that is a "pull" type force. It might stress the bars if he drives fast on bumpy ground and the hog bounces a lot but I don't think that would break them.
2: The other would be a "push" type force such as if he backs into an incline or backs into brush/trees forcing the rear of the hog to lift up. This could cause the two bars to try to bow outward and enough force like this could conceivably snap them. This is the most likely scenario I can see.
Nothing else makes much sense.

 

[Boatman62]

Ok, good to know they at least look correct.
I'm not sure why they would be "hardened" I would think it might make them more brittle.
Looking at where the break is and trying to compare to the picture it looks like the "bend" is further back or closer the mounting point in the picture I found.
May not be, hard to tell!

The only real force on those bars would be -
1: when lifting the brush hog but that is a "pull" type force. It might stress the bars if he drives fast on bumpy ground and the hog bounces a lot but I don't think that would break them.
2: The other would be a "push" type force such as if he backs into an incline or backs into brush/trees forcing the rear of the hog to lift up. This could cause the two bars to try to bow outward and enough force like this could conceivably snap them. This is the most likely scenario I can see.
Nothing else makes much sense.

I don't believe they would be hardened either,,, maybe a mistake in the manufacturing process.

They are breaking exactly at the point of the bend.

I never got a look at the first one that came original with the machine to see what the broken ends look like. But the two replacements look like they were compromised before installation.

 

[wirlybird]

I don't believe they would be hardened either,,, maybe a mistake in the manufacturing process.

They are breaking exactly at the point of the bend.

I never got a look at the first on that came original with the machine to see what the broken ends look like. But the two replacements look like they were compromised before installation.

Since they are breaking at the bend that is why I suspect that an excessive lifting at the rear of the hog is bending those bars outward until they break. Which is also unusual since I think they would just bend. I've bent them on one of mien but never broken one.
Really odd.

 

[LD1]

They aren't hardened. Looks like it's just cold rolled steel. Which is a very poor choice if it needs to be bent unless it's heated.

Question is....how old is the cutter. And is it still under warranty even though they are denying this claiming operator error?

I'd be inclined to seriously push back.

Not sure I'd cite manufacturing defect.....rather engineering defect of they spec'd cold roll and to bend it cold in a break

 

[Boatman62]

They aren't hardened. Looks like it's just cold rolled steel. Which is a very poor choice if it needs to be bent unless it's heated.

Question is....how old is the cutter. And is it still under warranty even though they are denying this claiming operator error?

I'd be inclined to seriously push back.

Not sure I'd cite manufacturing defect.....rather engineering defect of they spec'd cold roll and to bend it cold in a break

Don't know exactly but probably around 10 years old..... well out of the 1 year warranty.

I agree with the metallurgy.

 

[LD1]

Don't know exactly but probably around 10 years old..... well out of the 1 year warranty.

I agree with the metallurgy.

Either just go to a local shop and have them made out of hot rolled, or use some chain as another poster suggested

 

[hosspuller]

The ends of the break show a progressive cracking typical of a stress fracture. This happens under a cyclic loading. It usually starts at a material defect or stress riser. A bend qualifies for this definition. Either replace with chains or adjust the top link to allow the tail wheel to roll and follow the ground without loading these links..