hello, if I can ask, I saw in the workshop that they were replacing the spring of a broken tensioner, they cut the coils with the blowtorch torch, but how do you assemble and install the new spring compress it and assemble it without creating disasters? hydraulic press? sorry if I ask this trivial question for you professional veteran experts in the sector thank you
They use a big hydraulic press, usually at least one hundred ton in size. There is a specification given for how far the retaining nut is screwed on from the end of the retaining rod. The whole component is put in the press and the spring is compressed and the nut is then installed and screwed down to that specification. On some springs I've seen the spring is compressed to a certain tonnage seen on the press gauge and then the nut is put on.
I pulled this picture off of the web. We had a jig like this for assembling track springs. It was NOT my favorite job. The shop I was working at had a full fabrication and machine shop and engineering department. Building the press was not a big job, but it needs proper materials. There is a lot of force at play and you cannot take short cuts. Easiest thing to do is find a shop that can do it and get them to assemble it for you.
it would take a tube or a device that keeps the spring in compression but the fuse of the thread of the free tie rod to put the nut tighten it and tighten it properly, if you don't do it well you risk finishing the hospital I suppose. thanks for the technical clarification
It takes about 12 to 15 ton to press up a recoil on a CAT 951/955, around 15 to 18 ton to press up a Volvo 210 excavator recoil, I could go on but you also need a cylinder with a good stroke travel often over 6" to make things look easy, the task is only risky if you don't take care, I use a CAT 2 rod Service Press to do this work, CAT now have upgraded this tooling to a 3 rod system. tctractors
The rule of thumb from back when was the spring had the tonnage of the weight of the machine on crawlers and half the weight of the machine on excavators. In other words minimum tonnage on a 200 model excavator was at the least 10 metric tons of push on the spring. A forty ton dozer would have at a minimum 40 tons of push on the recoil spring. tctractors is correct in that it isn't that dangerous of project when you have the correct tools and knowledge. On the other hand it is very dangerous for the person that doesn't have the correct tools or knowledge.
thanks for the valuable tips. safety first. thank you