Ok to start this is not a post asking how this is done. Rather it is a post showing how I have done mine on a 955L with the D6 undercarriage. WARNING!!! I am in no way am saying this is how it should be done but am posting this information for educational purposes only. Anything one tries based off this information they do so at their own risk. This is not a job for the weak hart-ed. I am a mechanic with 25 years experience working on everything from heavy equipment, automotive, heavy truck, and even aircraft as well as welding, fabrication and machining. not tooting my own horn but just trying to show the level of expertise that has gone into this. Despite all this it still made me shake while doing this and if I said I was not scared that would be a lie! Ok so after cutting out my old springs (bang POP!) I purchased a set of aftermarket springs in KC. Drove up there and hauled them back in the back of a kia soul. hey what can I say its good on gas and the only thing I got with good air cond. Here is the main frame construction. it is 5" channel steel. all welds are vertical. absolutely no horizontal welds on the vertical uprights! a weld horizontally across the member causes a shoulder effect and causes a spot for a crack to develop or the spot for the catastrophic failure. All welds parallel with the direction of stress. Never perpendicular. next a top and bottom platten was added. 3/4" plate steel. the bottom one has hole for the spring pilot plate shoulder and rod/ nut to stick through. The top one has a ring welded on it for jack top to fit in so it cannot skin out during assembly. here is the rear pilot and spring loaded in the press after plattens installed.
Next the cylinder pilot was rebuilt with new tabs for the guides welded on. sandblasted and painted. pilot installed and a plate was made to press on top of pilot. the plate had a hole cut in center and an old junk clyinder was cut down and welded on with about 1.5" sticking into the pilot bore. this gives the 20 ton jack a place to set and with the side bars welded on to the plate it is all captured in the press and cannot skin out. keeps it all centered very nicely throughout the press cycle. Notice the ring for the top of the jack piston on top platten. with the jack out the whole thing can be slid out of the pilot assembly and turned sideways to remove or install into press and onto or off pilot assemble
Ok so i know what your thinking now. A jack does not have enough stroke. so we need a means to press about half way capture spring and extend jack screw and finish pressing. you can see this in this picture as spring is pressed about half way, 1.5" pins installed and jack retracted ready to reset. Now here is where it get fun and damn scary as the spring really develops force at this point. About an inch past the jack reset point the bolt is extending about one inch past rear pilot and huge arse nut can be installed and friction-ed up. Now we are in the safety zone. You would think that a feeling of comfort would come over you but it does not. I decided best thing to do at this point for safety sake is 5-6 pumps on jack and then tighten nut. this keeps nut close so if there is a catastrophic failure of press hopefully nut will catch and hold it without fail. it helped a bunch to have a forklift to lift it up to access nut after each jack repetition. after about 6-7 reps i had reached my mark. nut was tightened up and jack released and removed. Ahh sweet victory! And there it is ready to install into machine.
Ah the mother of inventive thinking, necessity. Looks like it did very well and yet I too would have been a little cautious approaching it with pressure mounting!
Hey thanks DMiller. I have got to say this is not something I wanted to do but was kind of pushed into it. The only place around here that can do that kind of work is the local cat dealer. seems that shouldn't have been a problem but when i asked how much to put it all together they wouldn't give me an answer and the old him and haw routine and questions about my used parts and so on. Ok so getting madder I asked if I had a pile of all brand new parts how much would it cost and I got same answer. So that makes me think one of two things. #1 there is no one left in their shop that can actually do the work or knows how to do the work as all the old guys retired and the shop is now filled with the worst generation of employees ever! or #2 They are counting on that you do not know what is involved and have no idea how long it should take. they tell you they don't know get it in the door then charge you an extraordinary amount for something that is an hours worth of work at the most. It is the second I am most likely to believe. I don't mind paying to have this done but i want to know what my cost is gona be and not be on an open ended billing sexual encounter. Jeremy
Do you mean the welds are done lengthwise with the channel or were welded in the vertical position? If the welds are sound and the right size, they don't need to be welded vertical. If this were a hydraulic press, 20 tons isn't very big but with the long spring, certainly need to pay attention.
Yes the welds are all done lengthwise with the channel. This way all the welds are parallel to the direction of stress. In this case it is a tension load. If you were to weld perpendicular to this line of stress then it give a shoulder effect where a crack can start. Just not good welding practice. Sometimes its not so much knowing where to weld as it is knowing where not to weld. In this case I did not weld the platens where they set against the verticals. This would have given a bead perpendicular to the lines of stress. I only welded the platens on each corner where they contact the cross members. On the 20 ton rating I was going by the cat book that stated the "compressed" spring force was 15 tons. I designed to that information. tried as hard as I could to design where spring could not skip out. I think I got a fairly safe rig despite my knees knocking while doing it lol.
Yair . . . workshoprat92 Job well done, I know the feeling . . . jacking on a spring is a different. (big grin) We made up horizontal bench rig that kept the springs contained in 14" heavy wall tubing, centred them with timber spacers . . . it gave an illogical sense of safety to what was potentially a hazardous operation. Cheers.
Well done. The only thing I would have added is some sort of retainer about midway along the length of the spring in case that thing decided to "squirt" out of there.
I think better terminology would make it less confusing. Welded vertical makes it sound like you welded it standing vertical. It's similar to welding on a backhoe boom.
Huh seemed pretty clear to me. I never said WELDED vertical. I said all welds ARE vertical.
Still have that setup ? Would you be interested in pressing a spring for me for my 941B ? I am located near pomme de terre .
Well credit to workshoprat for posting a good description and photo study of How To Get it Done, he understood the issue, he understood the loading involved taking an over the top safety margin to his frame and press components, possibly the only thing he never described is the weight involved as they are more than fair lumps to handle, so well done chap on a job lots would not have the Minerals in their blood to tackle, when I do a recoil job they still put me on wide alert as I know people who have been smashed about with the springs, I do have the correct tooling to do them on Site and show full respect to them until they are bolted in the frame, sad to say on lots of CAT track frames the back support is bent over years of hammer needing a strong repair. tctractors
YES ..so I took my spring to the cat dealer and same thing on a price quote . Dealers dont like helping owner operators anymore anyway because they are trying to put their rental machines on every job now and put the owner operators out of business... at least keep them from using their own machines. That started about 12 years ago . Pretty much all the dealers have went to that mentality . A machine owner walks up and the gouging begins . When the dealer gets done with them they will wish they didnt own any machines .