I was recently running an excavator and one of the pins in the bucket linkage broke. What’s everyone’s thoughts after looking at the picture of said pin that I took immediately after the damage was done.
Can you post a photo of the surface in your first photo but taken from straight on instead of at an angle..? The 2nd photo shows very little because of the grease covering most of the fracture surface.
From the picture you posted it appears it has been cracked for sometime. But Nige is right. A picture straight on would be more helpful.
Yeah, the pin has long since been taken from me. Machine has under 300 hours
The thing I’m wondering about is the dark line just to the left of the rust on the right side of the pin. After that you can see the coloring in the stages that the pin broke in.
Looks like it has been cracked long enough for rust to form on the 3/4 that was cracked...
They’re putting the blame on me instead of going back to the manufacturer with it. Everyone that knows equipment says there had to be a flaw. That dark line looks to me like a flaw that caused the rest of the pin to fail in stages
Here’s what I’m asking then. Operator error or a manufacturing defect?
I would say DEFECT
They wanted to write me up saying I broke it intentionally
X2 defect.
I wouldn’t even have an idea on how to break that intentionally. Management can be idiots
I have seen machines abused beyond belief. I don’t see how you could break that pin in that spot. Who knows. I’d tell them to stuff that pin if they want to blame you.
I did
Pin busted & failed . Makes me question if it was to " Hard " to begin with . There's a place for hard tempered steel only it will be more brittle & not handle the stress & shock load that a softer mix will . We use " Cold rolled " shaft for pins on the excavator . https://www.metalsupermarkets.com/metals/cold-rolled-steel/cold-rolled-steel-c1018-shafting/ You need a good "Blacksmith " to put the hoe back in action .
Really? how the hell do you break a pin intentionally? I would be breaking somebodies nose for that accusation.
That or they’d be walking around like Rob Lowe after his body cavity search in Wayne’s World!
I Wored for an outfit running TS-24's, the lead mechanic constantly blamed operators for breakdowns. I blew a rear engine when the trans harness shorted and the rear trans went to 2nd gear at full tilt boogie on the haul road... My fault and nearly got fired 'til the guy that found the problem spoke up. We had a guy named Zack on one machine that came into the shop one afternoon with a broken cutting edge, loading with 2 D9G's and an occasional 8K that would jump on and help. Lead mechanic started his blame game and got immediately flattened... Zach was 6'4" and 24" across the shoulders, he had enough of Mr. small mind and went to the office to turn in notice. Rest of us just watched, without offering any help. Next day was biz as usual, but the lead mechanic had his wings clipped and left shortly after when we started getting right back in his face.
If I break something or even have an inkling I did it I’ll take the heat. Try to throw me under the bus and it’s not gonna end well. Maybe not for me, him or both of us but everybody will know how the bear **** in the woods! Haha
I don't get to uptight about it anymore . Fire up the truck with the heater on it & put it back in order . Until the next time ….. Fire the truck up again .
It's near impossible for any of us to say for certain what caused this failure by simply looking at pictures. Yeah, could be caused by inferior design, no doubt. I once maintained a Cat 308C that bent the side links, machine only had a bucket attached, nothing else. The side links were a bit puny in my opinion. Ordered new ones, added some re-inforcement like one would find on links for a breaker machine and never had another problem with it, but there's no way I could prove the operator didn't do something insane to bend those links and instead fault Cat for a defect in engineering. All I did in remedy was to make it idiot proof, and it worked flawless after that. I notice you have a pin grabber coupler. Is there any other attachments that have been fitted to the machine?
Without any more photos to go on it's a bit hard, however on the basis of the posted photos I'd have initially said that this pin failed in fatigue over a long period. The reason I asked for more photos was to get a better look at the fracture face to see if it was possible to spot the crack inititation site because there are usually distinct signs pointing to it. Another reason I asked if more/better photos were available was that the material of the pin on the fracture face looked "kinda strange" for want of a better expression. Now with the additional information that the pin had less than 300 operating hours and it was implied that the operator broke it on purpose I'd call total & utter BS. That pin was defective from the start and it was a case of when it was going to fail, not if. Also if you think about it the location of the break in the pin makes no sense. It broke right in the centre of a bore in the H-link in which it was supported all the way along. If it had been truly overloaded, deliberately or not, then it should have broken right on or close to the junction of one bore in the linkage with another, in other words about 3" away from where it actually broke, if that makes sense. Edit: When I originally said "you can't see much in the 2nd photo, the fracture face is all covered in grease" I didn't think much of it at the time. However looking at it again the grease didn't get smeared on the broken end when the pin finally failed. The grease got on to that face because it's worked its way in through a crack in the pin. The last little bit on the bottom RH side without any grease was the clue, it's the only part of the pin that was still holding until it finally failed. IMHO the yellow colour on the broken ends of the pin was probably caused by the grease, so that should give some indication how long it was cracked before it finally broke. The autolube system on the machine must have been pushing grease into that crack for quite some time.
I appreciate everyone’s thoughts and input on this. No, there are no other attachments for the machine. There’s also no autolube, all greasing was done by my own loving hands.
My bad. I thought the lines in one of the photos were grease lines when in fact it appears as though they are the lines for the coupler. Serves me right for not looking close enough.
I would have quit working for any idiot that said that to me. Quite a putdown, it shows what he thinks of you. As stated -- defective pin.
Usually the dealers will always fault an operator in these cases. It happens a lot here and I see it constantly. They are on the plus side of these failures when the customer doesn't question them. I agree with everyone else...….the pin was fractured at some earlier point, finally broke into 2 pieces, and the free broken piece worked its way out until the force of the function twisted your forcing link side plate into a pretzel. Have the dealer explain to you why a pin that is locked into place with a retaining bolt broke between the 2 bushings inside the stick weldment. I personally would enjoy hearing their theory.
hey all , my 2cents worth, Definitly the pin Failure is unsual it looks to be in good shape not worn or sign of wear, just bad casting it should have shown a gray color where it cracked.
IMO that machine looks to good to have been abused bad enough to snap that pin in 300 hours. That pin definitely appears to have been fatigue fractured. I'd tell 'em where they can stick that busted pin.
Out here in my area, we have folks who dig foundation in "Chicago lots". They tend to not want to switch between bucket and hammer. So the bucket becomes the hammer. I have seen buckets with the bottom caved in. Pins still slide freely. Yer foreman is an *** for implying you could have possibly intentionally caused this. Additionally, Rockland (tefra) couplers aren't that strong. The coupler woulda failed first in my opinion.
I agree with Nige about it being a defective pin and it does look really strange. Generally when a brittle fracture like that happens you will see a smooth area with what looks like beach marks. Where the flaw was at would show little ridges or cracks perpendicular to the beach marks and they would point directly at the flaw. In this case the first photos shows dark coloring with a sudden area of lighter coloring and then on the other side of the pin opposite from the dark colored area we see almost white in color. It appears like there is no grain in the dark colored area and it kind of swirls around kind of like what you see in welding slag. The other issue I see is it looks almost like this pin was chromed instead of case hardened. If you look at the top section of the pin you can see a black line of the outer case or chrome what ever it is. If it is case hardened it is not nearly deep enough from what I've seen. My guess is that the metallurgy in the pin is faulty. Now here is a thought and I don't know what brand of machine it is or the coupler. But I have seen where manufacturers of couplers send pins with the units that are soft and meant to be installed in the bucket bosses. The original pins for the bucket are supposed to be used in the quick coupler. You see the soft pins are never meant to have a turning action on them. They are loaded into the bucket and the coupler jaws just grab them. You might just throw that question at the owners who can then relay that on to who ever sold and installed the coupler.
That failure came from the steel mill when they made the piece of round stock that the pin was eventually made from. The rough surface of the break completely across the diameter of the pin and the rust suggests it was broken for a long time. That break was hidden under a surface layer of some type--either it is chromed or maybe has a case hardening that hid the crack. It has been slowly cracking and finally went out during operations. If the shaft broke because of plain overload, (and not a defect in the steel) it still would be the manufacturers fault: improper relief valve settings on the hydraulics (too much push on the pin) , their engineers undersizing the pin, etc. Usually, these kind of failures can be recognized because the shaft starts to fail slowly, with a type of fracture that looks like sand on a lakeshore where the water level has been slowly moving down. The 10 dollar word for this is called "conchoidal fracture" and I've attached a picture from an engineering text showing what it typically would look like if it failed from overload "in place" and was originally a good shaft. Usually on this kind of slow cracking leading up to the final failure has rust on the "fatigue crack propagation" area because it takes time, maybe months-years to break far enough across the shaft to weaken it enough to hit "catastrophic" failure. Your particular failure does not have the signature smooth cracking that shows fatigue failure, and therefore I have to conclude it was cracked long before it became a pin in an excavator bucket. John C posted just as I was writing this--he and I are pretty much on the same page. Jon.
Thanks for all the input, just confirms what I knew already....it wasn’t abused. I’m the only one who has run this Deere since it was new and I know how I run equipment...hard but hardly abusive. I work for county government and have been here for 32 years. I suppose it shouldn’t surprise me that a couple of douchebags have no idea what they’re talking about. On a good note, my department head has convinced the insurance dept to send the pin out for analysis. I’m thinking it’s a win for me!
Does this loader load salt?
See if the dealer will cover you downtime while your at it. LOL
It’s an excavator and hasn’t been working in any type of corrosive atmosphere
1st break started on left center of attached photos. Pin material looks like C1045 induction hardened cylinder shafting with 0.0002"-0.0004" hard chrome. Photo #186304 ref: the hard chrome is peeling as seen on the right side of the photo. Also a circular wear line through the chrome @ inside of seal area; creates a stress point. Looks like slag inclusions (pocketed areas). 4 stages of breakage starting via the circular wear line. Failure @ 300hrs: Definitely not operator's fault! Couple links explaining hardness testing. https://www.hardnesstesters.com/test-types/case-depth-hardness-testing https://www.hardnesstesters.com/test-types/knoop-hardness-testing
Thank you
Got a picture of the eye on the end of the cylinder ? Bob
No, they swept it away to be repaired. I’ve now been grounded from running any equipment, guess they can pay me for sitting and watching someone that can’t run a machine.
Fireman, Reading between the lines, it sounds like a typical gov't outfit--the job isn't important, punishing anyone that actually does anything IS important. I'm hoping that there is a union on your side- one that is actually interested in standing up for their members. I'm with the guys who say get it fixed and get on with life!! I think the suits around you have got to number 5 on the list above. Best of luck on this. I'm rootin' for yuh! Jon.
Union isn’t required yet and don’t believe it will be. I know what’s going to come back from the pin analysis. Thanks for the encouragement. Oh, our bosses have been stuck on 5 for years
I feel sorry for you. I'm a civil engineer with our local county highway department - working on 47 years . I didn't even log in to increase the size of the photos. A blind man can see it has been cracked a long time. machine only has 300 hours, it wasn't you. Suspending you from operating, sorry your boss is an idiot. When I first started with the county, I was sent out as an inspector on a road project. They gave me PA-44 to drive, a whored out old IH survey panel truck. I took the back roads because it scared me. Exhaust fumes thru the back doors, way to much slop in the steering wheel, put on the brakes and it would pull left one time and right the next. Fortunately the job was only 3-4 miles from the office. Then they assigned me to a job about 15 miles away. needed to drive on the Interstate. I told my boss i wasn't driving it. He said write up all the problems and give it to the Equipment Supt. I did, he read my list, took the keys, threw them in his desk drawer and said "that will fix it". Their solution, give me another inspectors truck and told him to drive his own vehicle. I can still see his yellow polyster pants and pink polo shirt. Equip. Supt overseeing 85 plow trucks, graders, loaders, and dozers wearing yellow pants. Our fleet took a long time to recover from his "leadership". For the past 30 years, our trucks got washed regularly with a heavy duty power washer, soaped and then rinsed. (Once fancy pants left) Fleet looked good. Had a few 2nd shift part timers doing the washing. Drivers would if the trucks were really dirty. Winter time, 2nd shift washed trucks if it wasn't snowing. Not any more. Our fleet looks like crap.
I think doing some hardness testing of the pin would tell a lot. If the hardening process and/or metallurgy was wrong and never checked, the people assembling the machine would have no idea. Pins are generally sized for quite a big safety factor. I ripped the top swing mount off the backhoe on my 931B and it bent the bottom 1 1/2" thick plate. Pins were like new although they were 2 1/2" pins. The location of the break and the way it broke certainly doesn't point to abuse but does to a defective pin. 300 hours on a machine worth over 100K and they don't even consider warranty for a defective pin??? They should tell the JD if they don't warranty it, don't bother sending quotes when we're looking for more machines.
Been in the design business for 35 years. It would not be possible to break that pin in that location. Properly greased inbetween bushings inside the dipper....no effing way. Anyone that thinks differently, needs to have a jobsite accident. Ed
Pin breaking from 'sheer' force is not going to happen from the excavator's hydraulic power.
But they may miss out on a hunting trip, golf outing, or NASCAR race
Thats a metalurgical problem for sure. Your maintenance department might be better off getting after the dealer.Id be concerned about the rest of the pins. Think of doing a heavy lift and a boom cylinder pin does the same thing,seems unheard of but so is breaking a link pin like that. Years ago i was involved in building attachments and rigging up road building hoes. We made our pins out of 4340 htsr and sent them out for induction hardening. Never saw any kind of failure close that even under the worst abuse.
On an old Gold Rush episode, Fred broke the link connecting the bucket cylinder to the bucket on a Hitachi hoe. That's some of the worst abuse I've ever seen yet no problems with the pins.
Might not hurt to look at alignment also. Might have been forced in in a bind. Usually a combination of things to cause a failure.
I would be looking at the attachment's pin spacing! Those power links will spring open very easy. JD was sourcing pins manufactured in Canada, now offering US manufactured pins and cheaper prices.
I asked myself, "If it is at all possible to be abuse, what signs or abusee could do this?" On the first picture there is a yellow smudge on the bent link. Directly above the Coke bottle. If that link took a blow and was bent could it have contributed to the pin breaking? If someone backed a truck or ran a pay loader bucket into it while it was parked with the bucket on the ground then it could be damaged by someone and not give a metallurgy fault while still not being the fault of the excavator operator.
The pin shouldn't have broke. The break didn't happen from one blow and being inside the bushings indicates a tensile break from being pulled apart. How could do anything to pull the pin apart. The pin had to be defective to break like it did.
YEP! YEP! NOPE, not a tensile break; tensile comes from 'tension' = pulling from both ends until failure = tensile strength = testing material strength Look @ the photos benchmarks; notching failure, 1st crack started @ wear line and through the case hardening.
I'm in agreement with everyone that the pin shouldn't have broke. None of it should. I'm not convinced that the pin broke first. If the cylinder broke first and jammed the rod under the pin and between the broken casting the pin could have just been part of the carnage when everything let go. In that case metallurgy is going to say the pin was good and our op is going "under the bus". I agree the grease and patern on the pin look like a source of all the trouble but we haven't seen more.
OP, hasn't stated if the cylinder rod broke and hasn't provided a photo of the cylinder rod. Perhaps the OP will reply @ a latter date with some sort of 'results'.
Cylinder and all other parts in the area were fine. None of the linkage was bent prior to the pin breaking. Nothing backed into it or struck it from the side. The machine had been on 1 digging job for drainage pipe installation in topsoil and clay/sand. Then used to remove dead trees and topsoil in a wooded area. At the time everything gave way it was being used to pick wood, roots, etc from topsoil prior to screening out the smaller debris. The machine was never in a harsh environment such as demolition or digging through rock or anything substantial. The machine was used but not abused. I’ve seen New Holland machines and our old Deere put through much worse for far longer
I didn't word that right. It appears like the pin was just pulled part (brittle looking break). What I meant is the break was inside a bushing so the pin couldn't have broke from a bending type of force. The only other ways it could beak would be by tensile or a rotating force if part of the pin was seized, but it was regularly greased. I think the hyd's would fail before you could twist a bucket pin in two. My guess is the pin was too hard and brittle from either faulty pin material, improper hardening or a combination of both. Most of the break is older so 300 hours could be enough for metal fatigue to finally cause failure.