Weldable Backhoe Pin Bushings

[gdutson]

Hey guys,

I am converting an older Kubota cleanup bucket to fit my New Holland BH. Because the pin mount width and diameter is different I am starting over with new 1/2" thick flanges.

The New Holland pin diameter is 1.25". Does anyone know where I can source weldable bushings that I can weld into my new flanges?

Thanks,

Greg

 

[GPintheMitten]

Try DOM tube (drawn over mandrel). You can get pretty much whatever thickness and inside diameter you want. Probably want to go a about 10 thousands over the pin size. Still may have to ream them a little to be sure they are smooth inside but there is no internal weld seam.

Here's where I plan on getting mine for a loader build.

http://www.metalsdepot.com/products/hrsteel2.phtml?page=rndtube&LimAcc=$LimAcc

 

[gdutson]

Try DOM tube (drawn over mandrel). You can get pretty much whatever thickness and inside diameter you want. Probably want to go a about 10 thousands over the pin size. Still may have to ream them a little to be sure they are smooth inside but there is no internal weld seam.

Here's where I plan on getting mine for a loader build.

http://www.metalsdepot.com/products/hrsteel2.phtml?page=rndtube&LimAcc=$LimAcc

Hmmm. Good call...I can try and source that locally. I guess I will take my pins with me and check the fit. 10 thousands isn't much. Is that enough to keep grease in there?

I wonder what the OEM clearances are? Anybody know?

~G

 

[GE222]

Do you need to have bushings? Most buckets don't use them, as the pin doesn't rotate in the bucket ears. I had the same issue, except that I bought a used 9" bucket for trenching electrical lines, and I did the same thing you want to do.

I torched off the old ears, then welded a new 1/2" plate to the back of the bucket for a nice mounting surface.

Then, "Here is where I am fortunate", I drew up the new ear design in Auto CAD, gave the file to a co-worker, and it was loaded into a water saw - yes it cuts with a high pressure jet. I had 3-pair of ears cut, 2-pair were for future use.

I then cut 3/16" disks to go on the inside of the ears for spacers - I was matching the profile of my existing bucket, allowing the dipperstick to be offset from the inside of the bucket ear. The disks holes were milled to match the holes in the ears. The finished bucket is pretty tight when mounted.

I also made a jig to match the dipperstick profile to keep the ears parallel when welding.

The pins I also made new which will stay with the bucket.

I will upload up some pics this weekend of the finished bucket this weekend.


As an option for you, if you really want to go the bushing route, in another application for bushings, I used sprocket hubs. These are the kind that get welded to a sprocket, but are bored to closely match a shaft size. A pocket could be milled to fit the bucket ear, then weld the bushing on both sides. One drawback of using them is having a keyway cut in them. In my application I rotated the keyway in the direction that wouldn't receive any major force on it. After many years of use, they are as tight as ever.

 

[GPintheMitten]

Hmmm. Good call...I can try and source that locally. I guess I will take my pins with me and check the fit. 10 thousands isn't much. Is that enough to keep grease in there?

I wonder what the OEM clearances are? Anybody know?

~G

Well, you got me second guessing the clearance. Maybe it should be a bit more. I'm trying to find where I read that. As you can see I'm learning too.
I'm confident the DOM tube will be a good bushing but maybe not so confident about the clearances. Try to get other opinions.

 

[Sam Mac]

You could try something like this from McMaster Carr

McMaster-Carr

or give them a call and see what else they have that would work.

 

[true temper]

McMaster bushings won't work they are real hard, can't get a good weld. DOM tubing is what you want. .010 clearance might not be enough, when you weld them on the bushing shrinks some and you can't get your pin in. Plus when you weld them in they will draw some, make sure you have them lined up best you can.

 

[gdutson]

McMaster bushings won't work they are real hard, can't get a good weld. DOM tubing is what you want. .010 clearance might not be enough, when you weld them on the bushing shrinks some and you can't get your pin in. Plus when you weld them in they will draw some, make sure you have them lined up best you can.

The DOM tubing sounds like the way to go. It is softer metal than the pins which is appropriate. The pins mic out at 1.250". I have found some DOM tubing with 1.260" ID so I might go that route and figure on honing them out after I weld them into the brackets.

My thought was to put the pins into the bushings and then spot weld the bushings to the brackets, remove the pins and then do the final welding with the pins removed. I am a little concerned though hearing that the bushings will shrink during the weld.

 

[charlz]

If it looks like it is gonna be too close look for a local guy with a lathe to take a few thousands out of the bushing/DOM. I did this for one of my projects.

 

[jmc]

It is softer metal than the pins which is appropriate.

I would make sure that if it is going to wear, that the pin wears instead of the bushings.

As far as maintaining clearance during welding, one thing that worked for me was to wrap the pin in the thickest shim stock that will fit in the prewelded clearance, then weld the bushings while the pin/shim stock is in place. That way, after you hammer the pin out, you have clearance where the shim stock used to be.