Been awhile posting here but I've got a question so here goes. Long story short, pin for backhoe main boom cylinder slipped out of one ear on swing frame. Pin was still in cylinder rod end and one ear on the swing frame. Picked hoe up to reposition and all of the weight was being supported by the ear so it broke completely off. Has anyone successfully welded this piece back on? According to what I've been abl to see ( doing spark test with a grinder) the swing frame is made from cast iron. I was told it would be cast steel. Is there anyone that has any experience with this that can tell me for sure it's cast iron before I weld it up? Also if anyone has done this how well has the repair held up? I'm afraid if this is cast iron it's not going hold up to the stresses if it's welded. Thanks for any advice.
You may find this thread informative. HeavyEquipmentForums
This is a lot different than a Case 590 with high hours on a hammer, this is a vintage machine that failed ONLY because the pin came loose and the slop gave the pin leverage on the remaining ear. It wasn't just that the one ear took the load of both, it took the load at a bad angle. If it was me, I'd vee it out, and weld it with SS, (at least butter it with stainless or nickel, and regular rod for the filler), weld very small sections at a time with plenty of time to equalize the temp in between welds, peen the welds while hot, and see how it holds up.
The only information in that link that may help him is in regards to welding ductile iron if that is what he is dealing with. He is asking for help to determine what the boom mount is made from and the welding procedure. Sorry ala.millwright I can't help you with that. Can I assume you are a millwright ? All the millwrights I have known are experienced welders and fabricators.
Thanks for the replies fellows. Yes I am a millwright and proficient at welding and fab work. I assumed when the ear broke off the swing frame was made from cast steel, which is easily welded. I did a grinder spark test on the broken piece to make sure and according to the color and spray pattern of the sparks it's actually made from cast iron and not cast steel, which seems strange to me. Welding cast iron is a whole other process altogether and a pain in the rear. I really would like to know #1. If I am correct with my test results of this being iron vs steel #2. Has anyone done this before and it has held up to all the stresses of using the hoe. I can weld cast iron, however I've never had to weld iron on something that will see the stresses that this will and don't want to waste all the time and energy on this if it's just going to break again when it gets some good pressure on it from digging out a stump or something the first time out. There isn't any room on either side if the ear to weld a reinforcement plate. My thought was to v out the piece on both sides weld it up solid, then cut a piece of 1/2 steel form it over the top of the ear weld it down on the swing frame at both the top and bottom of where the ear would by welded back on. I feel this would help a great deal to add strength. Sorry for the long post but I'm just trying to be thorough with my explanation.
The swing tower is cast and generally can not be welded to original strength. I have seen repairs on a 300D and an early 310 may have been an A cant remember. The repairs looked good and from looks I would have expected them to hold. Sadly neither held and broke quickly after repair. Actual run time was under 10hrs for both machines. Exact same situation as yours the pin walked out due to wear and the ear broke from the tower. The swing towers on the two machines were not the same but made of the same material and the boom mounted in a similar way. One had a single swing cylinder and the other had twin swing cylinders. If it were mine I would give it a try but with the understanding that it is unlikely to work.
Yea that's what I was thinking also. Just hoping I was wrong. No telling what a good swing frame will cost, if I can even find a good used one.
Sorry, I didn't mean to dispute that thread, only to mention why I thought welding this ear would be reasonable, while welding the boom on the 590's didn't seem like such a great idea. I was assuming the spark test was correct and it was cast iron. I didn't know you were a millwright. It's hard to guess the level of experience we're dealing with sometimes. Sometimes you get an office guy asking an intelligent sounding question about an expensive piece of equipment, and sometimes you get an expert asking a simple question about an old lawn ornament, no offense to your Deere, fellow Deere lawn ornament owner myself.
The 310A is getting old but we have bought some for newer hoes in the $1500-$2000 range. There is a salvage yard in southern IL and a few AG yards in South East MO that would be worth a try. I don't have the names sorry. Wengers in PA also sells a lot of this type salvage.
Thanks for the info. I'm going to weld it and the backing plate across the top of the ear and see what happens
Hey ala.millwright: Could you post some pictures of your swing frame? Sometimes by getting a visual, it's easier to come up with an idea on how to go about fixing something. You just never know who is going to write in with a way to repair what you have.
I would be glad to post some pics of it, however I'm not sure how you attach pics on this forum.
Here is a link that explains it thoroughly.
I'm not sure if this is going to work. I'm trying to see if can use photobucket to post some pics from my iPhone.
Well it sorta worked. Anyone know how to post only the pic you are trying to post and not an entire album? Just disregard all the other pics of my bulldogs. That's my other hobby. Lol
Nice looking dogs Bad looking backhoe mount. Maybe you can go to the Shop Talk forum and find a post from Tom V. Send him an email or PM about your problem. He will have all the information you need as to whether you can weld that mount. There a lot of other members there that are professional welders. Too bad you can't post those pictures and your problem there, but double posts are not permitted. I can't help but wonder if there is unseen damage to the side that the pin is in.
It looks like you have plenty of meat left in the swing tower to fab a plate with a new pin holder and bolt it to the outside of the tower and weld the plate to the tower. It will take a longer pin and you might lose a little swing to that side but it defenitely looks fixable. From a weld the broken pieces back together stand point I dont think just welding is going to work.
looks like ductile iron=====cast iron/steel mixture probably won't weld
Thanks guys! I have thought about attaching a plate on the outside of the fix as well. I may end up doing the backing strap across the top like I described and one on the outside. Jimg984 it could be ductile iron. Not sure about that though.
The shop that I used to work at would sometimes deal with hard to repair parts like that one. If the parts turned out to be cast or ductile iron, we brazed them back together before adding plates. A lot of times we didn't even use backup plates when we were done brazing. A part like the one you have, we would bevel the broken edges then put the whole part in a half of a steel barrel, completely cover the part with charcoal and light it. We would leave the part in the barrel for at least six hours then start brazing. A part like that we would put the pin back in the holes to line up the broken pieces. We never had much luck welding on cast iron. There may be people out there that can weld cast, but it always seemed to eventually crack along the edge of the weld. I don't want to get into a dispute about whether cast iron can be welded or not, I'm just saying this is what we had good results with. A lot of the braze jobs would be on the slides for punch presses, so I know the repairs took one hell of a beating with a lot of shock loads.
Thanks Rust farmer! When you say y'all use to braze it instead of welding, did y'all use brass or silver solder?
We used brazing rod, it looked like brass. I don't know exactly what was in the rod, but it worked for cast iron. We used the bare brazing rod and just dipped the rod in a jar of flux. You can get brazing rod that is coated with flux, but we always used the bare stuff and dipped it in the flux. For a bigger job like yours you would want to get the bigger diameter rod. The cast iron parts were cherry red when we were doing the brazing. By cooking the part that long it helped cook all the grease out of the porous material. I forgot to mention that we would also wrap the part in insulation when we were done brazing to let the part cool slowly. I'm sure there are some people laughing while they read this, but we used to repair a lot of parts by brazing.
Yair . . . I don't think there would be too many rust farmer . It's an old and proven method. Way back I saw a blacksmith do it and after the brazing he cooled the part by burying in lime for a couple of days In later years on smaller cast iron parts I have had some success by preheating and welding with the TIG and using piston rings for filler rod. There are various fillers available that are meant to work with O/A but also seem to work better with the TIG. That 2% silver solder rod used by plumbers on copper pipe is handy too on a lot of oddball metals. A mate of mine found he could even weld 316 stainless onto brass and copper with the TIG. It saved a lot of messing around assembling process machinery he used to build. The machinery worked around salt water and I thought there may be some reaction between the metals but they have been going now for years. Cheers
with all the loose motion in the pins and bushings,,, and espi. the joints below the broken one.. you need a better frame section.. lots of force in those erea , I hate to be negative about brazing/welding.. remember you are asking for help not just someone to agree with you.. if want to have backhoe as a counter weight for front loader you could patch it to stay in place
Yair . . . It all comes back to time and effort but, looking at those pictures, I believe there may be scope to weld the lug and reinforce an overlayed (say) inch plate by drilling and tapping a couple of (say) inch and a quarter studs into that heavy boss section. It would not be hard to make cardboard patterns for the pieces and the pin hole and bolt holes would be no problem in the shop. Drilling and tapping the boss would not be easy in place but very doable with a magnetic base drill. When everything is checked for alignment weld around the heads of the bolts and edge of the plate(s) so it all becomes one piece . . . it will need a longer pin. As I said a lot of time and effort but I think a fairly good chance of working as the thrust will be transferred to the studs which are keyed immovably into the housing. Cheers.
Silicon bronze sticks in my mind as being one of the stronger brazing rods. Surfaces have to be VERY clean, just like you are soldering, to get the initial metal to bond with the cast. With the long cylinder and strong box section I think all of the side forces are designed to stay on the bottom pins but it's still a tough fix.
Thanks for all the suggestions guys. I haven't thought much about trying to braze this but I'm going to do a little research on brazing something like this vs welding. Don't do much brazing these days or very much cast iron repair for that matter. Lol