BH77 Repair Suggestions

[someguy9000]

If this should be in repair forum, my apologies. I put it here because my plan is to fab a bracket, to repair this.

Apologies for my bad artwork. My BH77 broke the pin between the two hydraulic rams in the middle. Ears flared out ect. Pin has been on backorder for a month, no tractor....total pain because this joint is IMO underengineered with 1/4 steel.

This is out of warranty, no Ktac. Im broke (who isnt these days) so im using a porta power to bend the ears back.

I'd like to avoid this happening again. My welding skills are not there. Im planning to i guess bolt a 3/4 plate, to this location on each side. Ill tie at the top with a bolt or something.

In the picture I attached (not my hoe) , (terrible drawing i know), the blue is the steel plate, the pink is a hole around the pin bushing, the greens are holes for a bolt. The bottom two are just to sandwich plate to the side. The top will be a bolt to span the two sides. Whomever hoe this was tried something similar.

Any thoughts if this is a good idea? Open other suggestions.

Tysm

 

[Paul Allwood]

Is it possible for you to post the pic without your artwork ? Are you also able to find and post an image of what it would look like if it wasn't broken ?

 

[someguy9000]

Sure. Pic on the top is the random internet picture, where someone tried something similar. Middle is my actual bh77 before bending it back. Bottom drawing is hopefully a other example of what im debating making to prevent this warping again.

 

[North Idaho Wolfman]

Forget all that drilling holes in the sides, that will just make it weaker, not stronger.
Drill a hole on the other side collar and use 2 grade 8 bolts to hold the pin on both sides.
Or use a pin with a head that butts up to the non pinned side.
This keeps the ears from being pushed apart.
A long bar in the pin hole will bend the ears right back into place.

 

[Runs With Scissors]

So the pin actually broke in half?

What sort of "maneuver" were you performing when it failed? (I ask this cause I think it would help to "engineer a fix" )

Could you post a picture of it?

I'm having a hard time picturing how this failure occurred.

However, off the top of my head, I agree with @North Idaho Wolfman , drilling holes might be a mistake....Like he suggests, I also think you need to focus on using a pins "tensile strength" to prevent this from happening again.

I'm not a machinist, just a "shadetree hack" acting like one occasionally , but if you need a pin made, I might be able to help you out.

I should be able to use my 77 as a template for the pin.

PM me if you're interested.

Your bracket seems to be relying on the thickness of the steel plates to prevent the bending again, but I don't think they are large enough, nor will they prevent this from happening again, rather it will bend where your brackets end.


If you want to use "big plates" I think you need to make them considerably larger than what your drawing shows, and a series of thru bolts along the outside, to prevent bending again.

I see your awful drawing, and raise you......

 

[someguy9000]

Yep broke in half. Working on a tree stump. Hard to know the exact move, but im sure the hydraulics are FAR stronger than the weak thin steel that mounts the pin on the boom arm. I have NO doubt this is going to bend the steel again now that its gotten weakened.

If you google it, I guess there were some bad pins and there was a recall. I have ordered a new one, but its taking forever through my dealer.

This pic isnt my pin, but mine broke in the same place, at the grease groove.

(And your drawing is better than mine)

Appreciate the idea. I would think "clamping" it like that would still allow it to bend inside the "clamp." Overall, I think this probably just isnt going to work.

 

[someguy9000]

Forget all that drilling holes in the sides, that will just make it weaker, not stronger.
Drill a hole on the other side collar and use 2 grade 8 bolts to hold the pin on both sides.
Or use a pin with a head that butts up to the non pinned side.
This keeps the ears from being pushed apart.
A long bar in the pin hole will bend the ears right back into place.

Yea second bolt on other collar is probably the best idea. Tyvm. I used a threaded rod to try to bring the ears together, but it wasnt really working well. Porta power with a short ram has been working well (enough)

 

[mdhughes]

FYI: BH77 with serial numbers between A0005 and A1209 are in the service bulletin based on the web search I did.

 

[someguy9000]

FYI: BH77 with serial numbers between A0005 and A1209 are in the service bulletin based on the web search I did.

Ill have to check mine for that. I discussed with my dealer, but with no ktac (their first question) I assumed im screwed.