howdy gents, just some questions for anyone thats done it before. One of my D8Ks has about 25-30 percent left all around. We are having an awfully wet miserable spring here, thus shop time is of a surplus. I am a good welder, have all the goodies, ac/dc miller stick, air arc, plasma, Hobart Mig. And I am looking into building up all my rollers and front idlers and possibly buying a new set of chains but building the old ones up next winter to keep as a spare. What kind of rod is best? I have never done it before, always just replaced with aftermarket TREK parts, but everything is getting so damn expensive, and all these parts are original cat parts i want to build up. I am thinking I will re bearing and seal the rollers because welding on them steady would likely burn the seals out anyhow. and what good is a built up roller with worn out bearings? Can you build it up to say 90 percent with 7018 or 223 and then fill the last bit with hard surface? or will that just chew the chain up too much? come on back fella's.
all things aside if it were me i'd run a dual shield wire through your mig.ESAB dual shield 7100 ultra wire with 100% co2 come to mind. you don't necessarily have to weld on the piece steady either one or two passes and letting it cool will maintain the crystalline structure and temper of the steel. just my 2c
Ive built Idlers up on alsorts of tracked machines and some rollers. I worked for a machine shop in the winter in callege and building up and turning the rollers we had to dissasemble them and take the bearings out. I toldthe boss who had weled his up on a little IH That was assemblesd that that wasnt a good idea. It workes like shinking a race out of a bore with a welder whne the wled cools it shrings and will bust the bearing. We had a jig set up and when we weled on up and let it cool Id bore out .005 to .010 and re asembe them. The only time around my family replacing an idler was when the bearing gave out. I worked one winter all winter on 3 old Cable 8s. This old man had some old spoke undercarriaged 8's pulling cable pans. he put D9 sprockets idlers and rollers and rails to make them go faster. I was out of a job one winter and tokke him up. I built up rails and idlers and weled in sprocket liners. Most times he could do that 4 times then the pins woul break in the rails. He had several of these machines.
welding I understand, trying to save money. I have never done this, but a friend of mine had 4 D6 dozers and they worked in muddy areas all the time and it was bad on the rollers, idlers, etc. He showed me a tank, that he made to rebuild the rollers. I think it was about 2-3ft long and the width, was the outer width of the rollers. He had flat bar welded on the inside of the tank, for the base of the roller to set on. I think the tank was about 2ft high. The tank had a connection to screw a water hose on and a discharge connection. I dont remember all the height and sizes of connection, but the purpose was the roller would be 1/3-1/2 submerged in running/flowing water, this keeps the seals from getting hot. He used this tank for about 6 years, before he sold his business. It may take some trail and error work, but it will work. The idlers, he said he used flatbar, to buildup the idler. He used flatbar, to buildup the teeth on the sprockets This all takes time, but it seems we have more time, than money. Good Luck
For years(over 40times 2 machines) my dad and uncle always welded the top rollers in sections(weld a 3 inch patch on both sides then rotate 180 do it again and go to the next. Never had an issue with bearings or seals as long as you just did it in sections and allowed for everything to cool down. Actually looking in our book its been over 6000 hours since we had replaced any of the top rollers, have to now on one as I did have a bearing go out but wasn't from welding it, as I hadn't done any on it for 2 years. In the next few days I'm going to be doing some, as I have the dozer in for winter(yeah in april) service finally. Replacing the track seals and doing some build up as well. Trbo
Here is a copy of the original cat info of weld repair/buildup back in the day......courtesy of edb from ACME......... http://www.redpowermagazine.com/forums/index.php?showtopic=35664&hl=
thanks for the link hardtail, very informative.
I know an owner operator who built a tank and shaft for rollers as well. He builds up all of his rollers and etc.. (HAS five D5'S) as well using the water to keep things cool as he welds.