Backhoe NEVER seen this before

[cantbeatadeere]

well, I was digging a stump out today with my 4710 w/ 448 backhoe and heard a pop sound, like metal broke?. looked around and didnt see anything, then my nephew asks " was this thing bent before"...shut the machien down and low and behold the bucket cyl. rod was bent into a complete j...actually more like a u:confused2:. long story short ---its costing me 300.00 to do a favor for a neighbor///////no good deed goes un-punished!!!:laughing:

 

[BethesdaEC]

Did you have the travel pins in? If the backhoe leaks down and hits something then something is going to give.

 

[Rustyiron]

The relief's should have dumped before the cyl bent, is this a new machine? (warranty?)
Any hyd. system/attachment is designed so that it is not able to self destruct when encountering a load beyond it's design limits, and it is properly adjusted and working. Either way you might check that out b4 this turns into a $600 favor!

 

[jd110]

Any hyd. system/attachment is designed so that it is not able to self destruct when encountering a load beyond it's design limits, and it is properly adjusted and working. Either way you might check that out b4 this turns into a $600 favor!

Any system operated properly should not self destruct either. A common mistake I have seen people make when digging out stumps is to engage the backhoe bucket into the stump or a root that the hydraulics can't move, and then try to pull it by pulling forward with the tractor. That puts more stress on the cylinder rod than it can stand. Another common mistake is to shim up or adjust the relief valve for more pressure. That also can cause a failure of this type. Neither one of these scenarios might have been at play here, but just thought it would be good to warn of the possible consequences while we are on the subject.

 

[Cidertom]

From my fun in 2007:
http://www.tractorbynet.com/forums/...rating/102027-448-bh-woops-whine-whimper.html

I was stationary. It just bent all on it's own. All I can think of is the geometry is slightly off resulting in a shear load. Several ops have reported this same failure mode since then on both the 448 and 447 hoes.

One concept is the hoe is being both dug (dipper stick) and lifted (boom) at the same time. I don't like that explanation but ...

Yep it happens...

 

[cantbeatadeere]

to be exact....I was trying to "snap" the roots buy getting under them with the teeth and then creating leverage with the back side of the bucket on the ground and then curling and pushing down on the boom at the same time, it has worked great diong this for the past four years I have owned it(bought new) but mayby it puts just enough fatigue on that part where it had had enough. it has never sat outside and is greased with equipment grease on a regular basis, so its not like neglect nor wear is a factor-----just have to take it back a notch now that I found the limit
just looked at cidertoms pick and mine was very sumilar just bent into a u