Backhoe Popped my BL4690 Backhoe Boom Lock Pin

[v8dave]

Henro, here is a picture of the end of a Kubota B4672A boom lock pin. Look familiar? The manual for my 'hoe covers both the B4672A and the BL4690B, looks like the same outfit makes both units. I'd say Kubota's subcontractor has a marginal approach to fastening this pin.

Looks like I need a pin welded too. Thanks for the heads up.

 

[ronjhall]

Dave
That looks just like mine. When I checked, there is a weld on inside of frame.

 

[PineRidge]

Nicely done Henro and I would suspect a lot stronger than the original ever was.

 

[Henro]

Dave,

Thanks for posting that picture. I would guess that is what mine looked like before it popped out. I never really paid attention to it...

Ron's is apparently welded in from the back side. If that had been the case with mine, I doubt it would have popped out. Mine had an indention in the back, that looked like it was deformed somehow, and that the deformation was what was keeping it in place.

There certainly was no welding on it, as can be seen in the photo showing the hole after the pin came our. Only rust, not a broken weld to be found anywhere.

From what I can see the repair I made is holding up well. Probably much better than what I got originally.

I'm not complaining though...the backhoe has become a close friend of mine over the last two years...we all have our shortcomings... /forums/images/graemlins/smile.gif

 

[v8dave]

It was hard to check that last night at near midnight. Good thing the tractor is inside now. I couldn't see the inside very well. The access was blocked on other side of backhoe with boxes I didn't feel like moving. Still moving into the new shop.

Anyway I did feel the inside and it didn't feel like it was welded to me.

 

[RayH]

Be careful not to forget that latch again. My pin is also pressed in (no weld) and I have also forgot to unlatch my boom and wondered why didnt they weld this thing like they did everything else. My conclusion was that its a built in weak point. That pin will pull out before damaging anything else. The next time you forget it, you may bend something that wont be as easy to fix. Im probably wrong but its just a thought.

 

[gray]

Hello Guys.

I have often not put my boom pin in and get the leak down that is normal? In any case, why doesn't Kuboat make a lever activated lock like some of the big hoes have??? I have a slide in pin on my L48 that I have thought of modifying into a lever type with a snap off bolt to guard against hoe damage.

It would be nice to just pull a lever and lock the boom up. I guess it is a money thing?

Henro. the weld is fine. I dont' weld much and when I do I hide them, grind them , paint them and hope my prep and penetration is good. Like some say--" ugly as a gorrila but strong as ****" Looks are nice but not everything.

Maybe ask Kubota about the pin being pressed in and if it is a safety thing? Mine is a slide through, there is no way it will release or break. I have tried to use my hoe a few times without removing the pin and had no issues. You could notch the latch bar at the pin a bit to let go if you aplied too much force???

Good fix.

 

[BoneheadNW]

</font><font color="blue" class="small">( I have often not put my boom pin in and get the leak down that is normal?)</font>

Nobody ever answered gray's question. Is it normal for the boom to leak down (with boom lock on or not) over a period of a day or two? The 4672 manual states "the boom lock should not be used when the unit is stored or parked". Does anyone out there lock their boom when the tractor is parked?

Bonehead

 

[Tollster]

Henro as an ASME certidied welding inspector I think you did a pretty good job. Good penetration, no excesive concavity or convexity, and nice transition between passes. Should last the life of the Kubota.

 

[avorancher]

I almost always use the lock on my 4672. Within a couple hours, it will leak down so that I cannot unlock it without raising the boom with the hydraulics.