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Thread: Komatsu sprocket removal

  1. #1
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    Komatsu sprocket removal

    I have looked everywhere(except in the manual which I don't have) for the procedure to remove the sprockets off my D20. I've used a puller till the bolts in the arms sheared off. Repaired it , tried again with a little heat on the sprocket while squirting water on the shaft. Rigged a 20 ton bottle jack and applied pressure with a port-a-power on the back side,,,all without budging it. I hope I haven't overlooked something really simple. Would anyone here be willing to share their methods. I sure would appreciate it. I'm taking the sprockets and tracks to a shop to have new pins and bushings, and rims. I hate to call and tell them I can't get the sprockets off.

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    If you are fitting new p/b what is your link height and the condition of the bolt holes? In my experience parts and labor to re-pin and bush on these small track groups can exceed the cost of brand new link assemblies.

    Like most old style final drives the sprocket rim is press fitted to the sprocket shaft. The sprocket needs to be pulled off the shaft (loosen the nut about 1/4" only).Make sure you press on the shaft and pull on the sprocket. Don't push on the back as you could damage the final drive.

    The sprocket is pressed on to between 10 to 20 tons but you may need a 50 ton cylinder or larger to pull it off.

    When a suitable puller is rigged up, pressing on the shaft and pulling on the rim, ensuring the nut is loose so that it can't fly off give the rim a sharp thwack with a big hammer and a lump of wood and it should come off.

    You will also need to press it back on and probably replace the sprocket seal

  3. #3
    Charter Member RonG's Avatar
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    I participated in the bottom rebuild of a D21 and we cut the spokes of the sprocket to remove it and welded the new one on in the same manner by cutting it on the same radius and fitting it on and welding it.
    I broke a 1/2" drive chinese ratchet with my bare hands on that job removing the bottom rollers.I couldn't do that again!!Ron G

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    Komatsu sprocket removal

    Thanks to all for the help. Got'em off !
    I really appreciate this website and all who make it
    what it is. GDW

  5. #5
    Super Moderator Orchard Ex's Avatar
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    What method did you use to get 'em off the shaft?
    I'll need to do mine one day...

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    Komatsu sprocket removal Reply to Thread

    Quote Originally Posted by Orchard Ex View Post
    What method did you use to get 'em off the shaft?
    I'll need to do mine one day...
    I used Wulf's suggestion. It worked on one side, but the other side, I had to strike the "jack screw" about three times. Maybe I didn't hit the back side hard enough?
    I used a regular two jaw automotive puller. The jack screw is about 3/4 inch fine thread, the jaws open to about 12inches. I initially sheard the bolts in the "arms" of the puller,,may not have tightened them up enough.
    I was probably over cautious at first because I didn't want to damage the bearings by beating on anything too hard.
    What about "pins & bushings" versus new chain assemblies. Have you had any experience comparing prices? I think you mentioned your tracks were still tight?
    I got a price of $1130 plus bolts for P&B(700 labor,430 parts). I thought new chains were several hundred more, but I really haven't checked them out too well.

  7. #7
    Super Moderator Orchard Ex's Avatar
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    If I remember right your PM said you still had 50% chain height. If it was me I wouldn't be buying new chain/rail now. I asked about the price of new track group a long time ago, I don't remember the price anymore but I do remember it was enough to convince me to run mine until they were gone, then do a complete rebuild.

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    RE Komatsu sprocket removal

    Quote Originally Posted by Orchard Ex View Post
    If I remember right your PM said you still had 50% chain height. If it was me I wouldn't be buying new chain/rail now. I asked about the price of new track group a long time ago, I don't remember the price anymore but I do remember it was enough to convince me to run mine until they were gone, then do a complete rebuild.
    You're right. I got a price today on the chains. It's about 650$ more than a P&B job. Not knowing any better,, I thought maybe the chain links themselves had stretched some. The guy at the shop I've been talking to seemed confident the chains would be ok as long as the heighth wasn't worn down too much. Yeah, you remembered right, mine measure to be 73mm, or about 50% wear.
    The shop is "Quick Trax of Texas", located just north of Houston in the Cypress area. They are very helpful, and willing to work with people like me, who need help.
    The guy said he would be inspecting 175 undercarriages for a construction company in Houston next week, but they like doing business with individuals as well. I'm going to replace 3 rollers while I'm at it. The ones at the "corners".
    I replaced one last year, along with the idler right by it.
    QuickTrax gave me a better price on rollers than the one I got last year,, seem like nice folks, guess I'll find out for sure when this is all done. Sorry for the long post. GDW

  9. #9
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    Quote Originally Posted by Wulf View Post

    Like most old style final drives the sprocket rim is press fitted to the sprocket shaft. The sprocket needs to be pulled off the shaft (loosen the nut about 1/4" only).Make sure you press on the shaft and pull on the sprocket. Don't push on the back as you could damage the final drive.

    The sprocket is pressed on to between 10 to 20 tons but you may need a 50 ton cylinder or larger to pull it off.

    When a suitable puller is rigged up, pressing on the shaft and pulling on the rim, ensuring the nut is loose so that it can't fly off give the rim a sharp thwack with a big hammer and a lump of wood and it should come off.

    You will also need to press it back on and probably replace the sprocket seal
    any ideas on how to press it back on for a dummy like me?
    thanks in advance
    keitho

  10. #10
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    I need to remove the sprockets on my Kabelco 907 clc It has 22 bolts, do you guys think this one is also pressed on. I got this excavator for my small farm, but the sprockets are a mess !!

  11. #11
    Senior Member iron kid's Avatar
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    any one have any luck with 61 ex i looking at a 2006 2100hrs loaded cab ac what should this costs?

  12. #12
    Senior Member AtlasRob's Avatar
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    Quote Originally Posted by stabber View Post
    It has 22 bolts, do you guys think this one is also pressed on.
    I am pretty confident that removing the bolts will release a circle with the teeth on the outside of said circle.
    I dont know for sure but suspect that progresss and innovation has moved us forward from the original problems ( for us DIY merchants ) of pressed on sprockets, to bolt on varieties that are sometimes a complete ring and sometimes segments.
    If their no good in the seat, put them on their feet.
    www.Robtaylorplanthireltd.co.uk

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