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Fixing shanks on an Excavator Bucket? Hardfacing as well

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  • Fixing shanks on an Excavator Bucket? Hardfacing as well

    I am a novice welder. have been doing alot of projects now for about a year. I have a miller bobcat 250 and a smaller mig 140. I have a friend with an excavator and the service rep sold him new teeth but when we put the teeth on they seem to have alot of play. They are the correct teeth for the bucket.

    But i seem to have read something a while ago about building up the shanks on the bucket to stop the play in the teeth. I was curious as to how i do this?

    Also I am interested in hardfacing his bucket and teeth. I was curious if someone can refer me to a source or fill me in on these techniques.


  • #2
    I assume you're talking about putting the teeth on the adapters and driving the retainers in . . . normally there will seem to be a lot of play at first, once they are used they should pack up with dirt and dust and it will firm them right up.

    Hardfacing material and techniques depend a lot on the material and soil types being worked with . . .


    • #3

      Well the guy from the cat dealership said that the shanks were kinda worn. Their certainly seems to be alot of play in the teeth and i assume that would only cause more wear.

      So i figured i could build up the the shanks and grind them down to a snug fit. Using 7018 or i was curious about using some hardfacing manganese rod because it would last longer.

      I would consider replacing the shanks but once again i've never taken on such a task. I assume i would just gouge out the existing weld on the shank, knock it off, grind it down, put on the next and use 7018 to weld it on. But then again i don't need the shank to fail on him because I failed to do something properly. I've never seen what a new shank looks like. Is it pre beveled? or what?

      As with hardfacing the excavator is used for general excavation purposes, foundations, trenching so just about anything is ran into. the guys at the welding supplier up here really only stock some manganese rod. Where can i look up some info on hardfacing?


      • #4
        We change bucket teeth often and if you dont change the shank they will be loose and usually come off. Really the best thing is for the operator to change the teeth before they wear to the point of weraing the shank. Have welded them with 7018 but use the MIG mostly. Just my 2 cents worth. I know they will come off from experience, I tried it with out replacing the shanks
        HMW [Heavy Metal welding]


        • #5
          Oh, one more thing. for hard facing we use Forney "super wear" rods. 5/32"
          But we dont do the buckets only the plow blades. Hard to grind that stuff off. The shanks we get from Ditch Witch are not beveled but its easy to put a small bevel on them. Also most of the stress on them is in compression, so although the weld should be good, you'll do fine. The 140 is not big enough but the Bobcat is for sure. Good luck
          HMW [Heavy Metal welding]


          • #6
            1)If they are not to bad they will pack up with dirt as calweld says. 2)You can just run some beads on them & grind them for a snug fit also. 7018 will work fine. 3)To replace them do as you say, gouge them off, grind, weld new ones on. Not a big deal. 7018 also. The ones I use are beveled. I just grind off everything clean then weld.
            Trailblazer 250g
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            Victor O/A
            MM200 black face
            Whitney 30 ton hydraulic punch
            Lown 1/8x 36" power roller
            Arco roto-phase model M
            Vectrax 7x12 band saw
            Miller spectrum 875
            30a spoolgun w/wc-24
            Syncrowave 250


            • #7
              Stoody is the brand name for hardsurfacing just about anything. We just hardfaced the frog and sides of a 980 loader bucket with Stoody 101HC, .045 wire. Gave it two passes, should last another 5 years. 33 lb spool ... bout 300 bucks. Used bout a spool and a quarter. 101HC is high on abrasion but lower on the impact. They have info on how to hard surface just about anything and will assist you lots.
              As for bucket teeth, you could hard surface them, but only the sides and tops, and total coverage would last longest. Or just replace the teeth as needed. The shanks are protected by the teeth so none needed there.
              Even with new shanks and pins, the teeth are loose by design.
              Maganese build up rod is just that. Used to build up worn away metal prior to hard surfacing. Mainly used for crushers or high impact, it is low on the abrasion scale by itself but takes a licking and keeps on ticking. Hope this helps.


              • #8
                If it's a Cat tooth the salesman should be able to supply you with the info for the proper procedure for build-up of the shank (preheat,profile,etc) and the best method and pattern for the hardface.I have the info on Hensley,Deere and Esco but I'm not familier with what Cat uses. HTH Bill


                • #9
                  They should be pre beveled . You gotta gouge way in to burn them off. They are always gonna be a bit loose when you first put them on. I don't change them unless they are warn downto almost nothing on the bottom side of the bucket or they crack. They will pack up with dirt and should stay on. Cat and Esco teeth will stay on pretty well even if a little warn because of their design. Always preheat for buildup or replacement. 7018 works well and also E71M wire but the wire tends to put alot of heat in and can lead to cracks sometimes, peening really helps that problem. I hardsurface with Lincoln Wearshield 60. Lasts a long time. Or if using wire I use Lincore 60. Dave


                  • #10
                    Originally posted by the hat View Post
                    If it's a Cat tooth the salesman should be able to supply you with the info for the proper procedure for build-up of the shank (preheat,profile,etc) and the best method and pattern for the hardface.I have the info on Hensley,Deere and Esco but I'm not familier with what Cat uses. HTH Bill
                    Can you pass on that info? is that digital or not?



                    • #11
                      PM what setup your working on and I'll make copys and fax them to you. Bill


                      • #12
                        I work for a CAT dealership, and the new shanks/adapters always are loose fitting onto the teeth. The only time we change an adapter/shank is when the bucket was run without the tooth on it, wearing the shank beyond useabillity.

                        I've changed many adapters for different reasons, but the process stays the same. I've never (by my own means or by CAT specs) had to build up or hard face the adapters. The cutting edge/frog plate is a hardened part usually falling into the specs of A400F. There are others used for this purpose, but CAT specifies a procedure for the changing of the adapters.

                        Gouge the old ones off, preheat the plate to 300 -375 degrees F, and weld the new ones on. Don't let the inter-pass temp drop below 250 deg F or go above 450. Allow the weldment to cool slowly. Start at the edge of the frog, and weld upto the back of the shank, either around the back of the adapter or not, trailling off in a 45 deg run off. Use 8018-c3 or any wire or rod equivellent.

                        As for hard facing and build up of the adapters for better tool engagement, you can build them up with an 80,000 psi rod or wire using preheat as described without problems. I have never personally hard faced the adapters.

                        The new teeth will fit loosely to any adapter, so take that into consideration. Dirt packs in and all is good. New adapters come with a bevel, which takes one or two passes to fill before you put the final cap on which consists of three to six passes, depending on the size of the shank.

                        Hope this helps

                        Dynasty 300DX
                        Esab PCM 1000


                        • #13
                          I agree with a couple other posts. We don't change the shanks unless the teeth have been missing. [which is often] They are a little loose when in good shape, but will be sloppy if ran without a tooth on the shank. You can kinda tell if the shank is wore alot. If just his teeth are wore down, just change them. In my case usually half are missing..
                          HMW [Heavy Metal welding]