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undercarriage work

ktm250rider ยท 2010-10-15 08:36

I knew it was coming. I found a broken tip on one of my drive sprockets. The teeth were worn to a point when I bought the machine but the price was right. The machine has about 8500 hrs and the bushings seem to be worn as well. Cant gage the idler wheel for wear, it looks pretty good to me. The shoes are in good condition. Could I just replace the drive sprockets and not worry about the other undercarriage components? Im using the machine around the house so I wont be putting many hours on it, while i own it. I dont have a price on the bushings but the sprocket and idler wheel are about $1100 per side.

Replies23
  1. #1xcmark2010-10-15 09:28

    If your only looking to get a 100 hours out of the bottom end and resell it maybe see if there is any used parts around. Changeing the entire under carrage on a high our machine is going to get very expensive !

  2. #2ktm250rider2010-10-15 10:04

    Ive thought of used parts. Cant seem to find any links for them.

  3. #3captain charlie2010-10-15 11:30

    You might want to take it to a welder and have him build up the broken tip and add more weld to other tips and reshape them. Good time to check the idlers and rollers for wear and tear.

  4. #4JDOFMEMI2010-10-15 15:16

    What size machine are you talking about? The answer may be different depending on whether you are talking about a 3 ton mini, a 45 ton machine, or, more likely, something in between.

  5. #5ktm250rider2010-10-15 15:52

    woops, Hyundai 130 LC3

  6. #6JDOFMEMI2010-10-15 16:06

    Look into an aftermarket sprocket. Berco may be helpful to you. If it was a production machine, it would be different, but for home use, the cheaper parts would do fine for you. Any pictures?

  7. #7ktm250rider2010-10-15 17:27

    The sprocket is actually the cheap part. I can get a pair 400 bucks. Its the idler wheel thats 900 per side and Im not sure what the bushings would be. I got pics somewhere, ill try to get them up.

  8. #8JDOFMEMI2010-10-15 17:39

    I have rarely seen a problem with idlers on an excavator. They dont travel enough to wear out like a dozer. I have seen them crack due to the constant impact in rough digging. I just weld them and keep going. If it wears out, the flange will get thin, and then it will crack at the edge of the center hump. With excavators, the main problem is the pin wear inside the bushings. This is due mainly to flexing over the ground. The bushings rarely wear out on the outside before the internal pins have wore to the breaking point. I have ran many machines with the sprockets looking pretty bad. Depends on what you do with it how big of a deal it is. Mine mainly load trucks on relatively smooth ground, only climbing to get on a bench. Then I pull with the stick to help. If you do any work on a slope, it is much more important to keep it in good shape.

  9. #9DirtHauler2010-10-15 18:09

    I would not worry about it if that is all your doing. One broken tip on a tooth in your situation does not justify replaceing it. BUT do keep an extra close eye on the sproket and if you notice it acting any differently now than it did before then that changes things.

  10. #10thebaz2010-10-15 19:25

    The thing to check is whether the pins are worn to the point where the bushes are out of pitch with the sprocket, as this will cause the bush to ride up to the tip of the sprocket and then compress the spring on the track adjuster till it releases with a bang. This is possibly what broke the tip off the tooth in the first place. If this is the case new sprockets will not help much. If the sprocket is not skipping or slipping when you travel you may get your 100 hrs without having to do anything.

  11. #11RonG2010-10-16 03:59

    One of my brothers lives in Canterbury,he used to own Merrimac Sheet Metal until he retired.Ron G

  12. #12ktm250rider2010-10-16 11:13

    Uh ohh, this is what may be happening, I need to verify. Crap, I really didnt want to have to replace the bushings. May be a winter job. PUll the track into the basement and go to work.

  13. #13QuickTrax2010-10-16 12:32

    ktm250rider, The easiest way to check if your pins and bushings are wore out is to look at the brackets on your idlers. If they are sticking out of the roller frames means they have a lot of wear and you don't have long until you start breaking pins. If they are not out of the frames and your sprockets are not jumping over you should keep running the machine. Once your sprockets start jumping over I would put new sprockets on it and go until the pins and bushings are junk. At that point I would go to your local track shop and get new pins and bushings installed into your chains and put new sprockets on again. At the time that you need to do something about your pins and bushings, check the new chain price also to see which one is cheaper. This is how you would get the most bang for your buck. Good luck, Quicktrax

  14. #14Hanomag2010-10-16 15:46

    The easiest way to extend the life of the tracks is to remove one complete link from each track (your machines front idlers are probably hanging off the end of the track frames). Just cut out one link, you might need to weld the track pins in. If you are only going run a hundred hours a year the above will work. If you decide to re-track the machine buy complete chains as the old track links will not take new bushes (the bores in the links will be stretched because of the hours and the wide excavator shoes). Get as much life as you can out of the old tracks before spending money on new. Regards

  15. #15ktm250rider2010-10-16 19:18

    Is it possible to replace the bushings myself? What tools are needed, can I just drive them out. I think i need a parts break down on the machine. It looks like the bushings are junk. Some are actully worn right through so I can see the pin on the inside.

  16. #16Jam2010-10-16 19:40

    If you can see your pins those tracks are scrap im afraid

  17. #17thebaz2010-10-17 03:49

    There is pretty much no way you can do pins and bushings without the special track press and then you would have to know how to use it. These pins and bushes are pushed in with hundreds of tons of force so it is both difficult and potentially dangerous. Once the bushes are worn through to the pins, you reduce the chance of successful pin and bush replacement and replacing the whole chain is often more economical and a better option in the long run. The only cheep way out is to get used parts that are still serviceable. Unless your idler and rollers have unserviceable bearings, you can generally still get away with using them if they are worn, as a good chain will still travel reasonably true and not come off too easily, however an undercarriage is only as strong as it's weakest link and any worn part will cause a problem. Since you are only going to do a small amount of hours you will have to at least start with the chains and sprockets and see how you go.

  18. #18RonG2010-10-17 04:52

    Whippy ding,huh?Ron G

  19. #19QuickTrax2010-10-17 11:14

    You would need a track press. I have never heard of someone replacing the pins and bushings without a track press. Even though your bushings are worn to the pin, you could still install new pins and bushings into your links. We have three track presses and we do it all the time. You could find your closest track shop and see if they have someone who could look at your machine. Most shops will send someone out at no charge hoping to get the work. Your machine takes the same chain as the CAT 312. This is a very common chain so aftermarket parts should be readily available. Be sure to check the price of a new chain vs. pins and bushings. I believe a new aftermarket chain should run around $1150-$1200. Good luck, Quicktrax

  20. #20ktm250rider2010-10-17 15:11

    Thanks, ill look around. $1200 isnt as bad as i was thinking.

  21. #21thebaz2010-10-18 00:00

    I think the first set of pins and bushes I put in my Case 455C cost $2000aud in 1988 without the cost of installing them in the chains. Things have definitely improved cost wise for undercariage

  22. #22ktm250rider2010-10-20 12:07

    Looks about 2500 for both sides. Got a couple quotes which vary by $700. That doesnt include the money I could probably get for scrap steel. Whats the best process for swapping them? Should I take the shoes off the old track while its on the machine and then put them back on when the chain is on the machine. Or, take the shoes off after removing the track from the machine?

  23. #23QuickTrax2010-10-20 12:41

    Most of our customers who swap the pads themselves remove the shoes while the tracks are still on the machine. They then install the new chains onto the machine without the pads and install the pads onto the new chain. Be sure to have a cutting torch handy because very rarely do all of the bolts come off easy. Be sure to dip your bolts in oil or grease before installing the pads back onto the new chains and remove the paint from the mounting surface before installing the pads. Good luck, Quicktrax