Dealer says the Boom locking pin is for safety. If the hydraulic hose ruptures it would prevent an accident. He said the boom pin repair is not a warranty item, noticed around page 14 another BH90 owner had same pin fallout. Should the pin fallout or shear if you accidentally push "down" boom when LOCKED????? Anybody else have this happen??
3130-Backhoe 4690 Boom PIN fell out -purpose?
- Thread starter ramon49
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rswyan
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</font><font color="blue" class="small">( Dealer says the Boom locking pin is for safety. )</font>
You betcha.
</font><font color="blue" class="small">( He said the boom pin repair is not a warranty item Should the pin fallout or shear if you accidentally push "down" boom when LOCKED????? )</font>
If it came out as a result of the boom being pushed down, no I don't think it would (or should be) a warranty item. The lock pin is designed to support the weight of the boom, dipperstick, cylinders, and bucket when the 'hoe is not being used. The weight of those items is probably not more than 800 lbs. - the boom cylinder however is capable of generating a downforce of over 6000 lbs. The pin is not designed to handle that kind of force. If the pin didn't come out/shear off, it's possible that there would be other more expensive to repair damage that could occur.
</font><font color="blue" class="small">( Anybody else have this happen?? )</font>
I think there was a thread recently where the boom lock pin on a BL4690 'hoe (could have been a BH90) came out - as I recall the pin was welded on one side only (outside) of the plate it was in. I believe when the person repaired it they welded both sides.
You betcha.
</font><font color="blue" class="small">( He said the boom pin repair is not a warranty item Should the pin fallout or shear if you accidentally push "down" boom when LOCKED????? )</font>
If it came out as a result of the boom being pushed down, no I don't think it would (or should be) a warranty item. The lock pin is designed to support the weight of the boom, dipperstick, cylinders, and bucket when the 'hoe is not being used. The weight of those items is probably not more than 800 lbs. - the boom cylinder however is capable of generating a downforce of over 6000 lbs. The pin is not designed to handle that kind of force. If the pin didn't come out/shear off, it's possible that there would be other more expensive to repair damage that could occur.
</font><font color="blue" class="small">( Anybody else have this happen?? )</font>
I think there was a thread recently where the boom lock pin on a BL4690 'hoe (could have been a BH90) came out - as I recall the pin was welded on one side only (outside) of the plate it was in. I believe when the person repaired it they welded both sides.
ronjhall
Super Star Member
Here is a thread about the same problem. Click Here
According to thread there was no weld on pin. Repair was made by owner.
According to thread there was no weld on pin. Repair was made by owner.
Henro
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The way I see it is if the pin is weak enough in design to be damaged by a simple mistake of forgetting the boom is locked to it, then it is a poor safety device at best. It could be unknowingly weakened and fail when called up at a later time. I think one might call it poor design.
In my case what did not make sense to me was the fact that one pin was welded into/onto the boom, but the pin on the "stationary" side was simply pressed into a hole and deformed slightly, with no weld or anything but friction to hold it in place.
Sounds like the same design has carried over to the BH90. Would there be a reason for this? Or is it simply "We always did it this way?" What I did was copy what Kubota did on the boom side pin and all seems well now with my BL4690...I doubt that pin will pop out again! /forums/images/graemlins/smile.gif
In my case what did not make sense to me was the fact that one pin was welded into/onto the boom, but the pin on the "stationary" side was simply pressed into a hole and deformed slightly, with no weld or anything but friction to hold it in place.
Sounds like the same design has carried over to the BH90. Would there be a reason for this? Or is it simply "We always did it this way?" What I did was copy what Kubota did on the boom side pin and all seems well now with my BL4690...I doubt that pin will pop out again! /forums/images/graemlins/smile.gif
RobS
Super Member
<font color="blue"> the boom cylinder however is capable of generating a downforce of over 6000 lbs </font>
Most likely the boom force will be a lot lower in the raised position due to the geometry of the pivot points. I don't know for sure (because I didn't sleep in a Holiday Inn Express last night), but it wouldn't surprise me if the boom lock would hold the force of the boom while raised. I'm also not going to experiment on my hoe /forums/images/graemlins/smile.gif
Most likely the boom force will be a lot lower in the raised position due to the geometry of the pivot points. I don't know for sure (because I didn't sleep in a Holiday Inn Express last night), but it wouldn't surprise me if the boom lock would hold the force of the boom while raised. I'm also not going to experiment on my hoe /forums/images/graemlins/smile.gif
ronjhall
Super Star Member
<font color="blue"> 3130-Backhoe 4690 Boom PIN fell out -purpose? </font>
I'm confused. /forums/images/graemlins/confused.gif
Is this post about a 4690 or BH90?
I'm confused. /forums/images/graemlins/confused.gif
Is this post about a 4690 or BH90?
Henro
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Ron,
I thought I was the confused one, after reading your last post. But now I KNOW I am confused...
I read BH90 in the body of the original post, but now see the 4690 in thread title again... /forums/images/graemlins/confused.gif
Which backhoe was the post about? Guess after posting this I will have to go back to the top and start reading again... /forums/images/graemlins/crazy.gif
I thought I was the confused one, after reading your last post. But now I KNOW I am confused...
I read BH90 in the body of the original post, but now see the 4690 in thread title again... /forums/images/graemlins/confused.gif
Which backhoe was the post about? Guess after posting this I will have to go back to the top and start reading again... /forums/images/graemlins/crazy.gif
JerryG
Super Member
I know that this discussion is about the boom pin on a Kubota. But, I just wonder what other manufacturers do. On both Massey Ferguson backhoes that I have owned, they were welded in solid. If you have a different brand, how are they made?
