Oops steel breaks

Don't you just hate it when that happens.

Was this from overloading it/misuse, or a defect that eventually failed?

Looks like the new "quick detach" bucket has arrived!

i thought the holes in arms like that made them stronger. guess not.

I've been thinking about this photo since I took my first look, and from what I see, I THINK what may have happened here, is a hydraulic cylinder, hose, or plumbing problem...

Notice that while the closest lift arm is up high, the far (right) side is only partially up... and there's very little load in the bucket.

These lift arms are plenty svelte.  Typically, older wheel loaders I've operated were gravity down only, while some newer ones had downpressure.  Regardless of how they were valved, every one had a hose to both sides of the cylinder, as if it were actually being used in double-acting mode.  The reason for doing so, is to prevent having the 'unused' side of a single acting system vented out in the dusty-dirty area of the working world.  Instead of venting, the unused line would either be piped to a remotely filtered place, or piped to the tank or valving, so that any displacement airflow came from 'within' the protected environment of the hydraulic system.

These lift arms are incredibly strong... they have to be, to take the day-in/day-out industrial/mining workload and yield high reliability.  The one thing, however, that will tragically weaken the lift arms, is if one is subjected to not only it's own workload, but workload of the other side...

I believe that probably what happened here, is that one of the cylinders either jammed due to a mechanical issue, or the hydraulic system suffered some sort of blockage that prevented one cylinder from doing 'it's fair share'.  (sorry, just couldn't help putting that in).

While loss of one cylinder wouldn't result in having the thing rip in two on the first shot, a long-term imbalance between the cylinders would fatigue the lift arms just as the photo indicates... not to mention being really hard on pins 'n stuff...

I see the cables to to which you refer... (and the ratchet-strap in place obviously to protect neighborhood passers-by from walking their dogs into a dangerous place)...

The cables don't look like something suitable for recovery... they do, however, look like armor-jacketed electronic signalling cables coming from the load pins (strain gauges) to the cab-mounted scale indicator.

Anybody on here work at the Peoria facility?  chime in and tell me- are those arms cast billet, forged, or fabricated?  These appear to be forged, while very loader I've operated was fabricated steel (doesn't mean much, as I've never operated one quite that big)... but my local quarry has one a little smaller in chassis size, with about the same sized bucket (no teeth), and it's fab'd.  I'm sure that if those arms are cast billet,  they're soft specifically for this reason.

I imagine that repair job somewhat sucked.



Edited by DaveKamp - 08 Jul 2012 at 12:24pm

Coke, who was drivin, and did he blame it on the previous shift's operator?

There is a large, heavy wall piece of tubing (looks to be 16 to 24 inches in diameter) that connects the two lift arms this keeps them in line/sync as the hydraulics will allow all the lift go to the light side of the load. That tube extents about half way through the life arm it is then welded between the end of the tube and the inside of the hole in the lift arm on the outside of the arm. On the inside, of the arm the weld is on the outside of the tube to that side of the arm. Looking at the break it follows that inside weld right around the tube. Probably that weld was not properly cooled at the factory and it weakened the metal just outside the weld. Eventually that metal cracked and the short pieces on the ends of the crack could not hold.