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Cat 305C – Some loose in thumb/bucket attachments

Extra Fubar · 2018-05-13 11:01

Hi guys, Second weekend here using my 2008 CAT 305C CR - mainly moving around big rocks. I took two videos showing some loose in the thumb and the bucket (24") - here is the video for the thumb: ... and here is the video for the bucket: With that much loose, would you suggest replacing the pins and bushings? I do not want to damage the equipment by using it with too much loose, and I don't know what is too much. Thanks,

Replies21
  1. #1ycs2018-05-14 21:19

    I wouldn't worry about the thumb, put some new washer on both side the movement will go away. The bucket pin might need replacing..

  2. #2Nige2018-05-15 09:42

    From the videos - 2 comments. 1. The side float in the linkage can easily be taken up with either more spacers in the same locations you have them now, or with new thicker spacers. Your call. Don't take out all the side float - it might give you problems with the linkage. Maybe 3-5mm total sideways movement should be a maximum, right now you probably have 15-20mm. 2. Hard to tell from the video but the quick coupler jaw appears to be "well worn". It could be a combination of wear in the jaw and also wear in the pins on the bucket but it's hard to tell with the bucket installed. Not such an easy fix........

  3. #3Extra Fubar2018-05-15 09:52

    Thanks for your comments guys, they are very much appreciated. I agree about the thumb's attachment spacers - I'll look into ordering some more. As for the coupler jaw/pin, I'll try to inspect the coupler a bit more. What can be done if it's well worn? Call a welder to fix this before getting new pins?

  4. #4Nige2018-05-15 10:14

    I suggest to remove the bucket and take a photo of the pin where it fits in the jaw of the coupler. That photo will quickly reveal whether or not the pin is worn. Attack the worn pin first and then figure out what to do with the jaw of the QC would be my thought.

  5. #5Extra Fubar2018-05-15 10:42

    Won't a new pin on a worn coupler quickly damage the pin?

  6. #6Nige2018-05-15 11:10

    look at it this way. Right now you know both are worn - the only way to figure out what the wear is in the coupler side, unless you have dimensioned factory drawings of it (and I’m assuming that you don’t) is to put a new pin into it. The new pin doesn’t have to be installed in a bucket to do that....

  7. #7Extra Fubar2018-05-15 11:25

    Thanks Nige - I'll inspect things over the weekend and order the proper pins. When I looked at the Cat parts manual yesterday, it wasn't clear to me which pins would work as there were 3 diagrams showing the same pins with different part numbers.

  8. #8Extra Fubar2018-05-15 19:54

    So, bucket pins - 279-4300 or 282-1692?

  9. #9Nige2018-05-15 20:59

    Sorry I’m just about to set off travelling for a few days. Hopefully someone else can help you. It would greatly assist if you posted the machine Serial Number.

  10. #10Extra Fubar2018-05-15 21:03

    No worry Nige! My serial number is HWJ03046. Safe travelling for you sir!

  11. #11Nige2018-05-17 06:56

    Pin for the bucket as shown in your 2nd video is 279-4300. Looking again at the video I'm not sure there is a lot of wear in that pin although it may be bent. It's difficult to tell. However a new pin is the only way you can work out how much the jaw of the QC needs rebuilding. Also I can tell you that your machine was not equipped with a QC when it was first built in 2008. Unless you have bought parts for the coupler previously from Cat then it may not be a Cat coupler at all - if it is Cat there ought to be a Serial Number plate on it somewhere. Not necessarily a bad thing but something you need to be aware of.

  12. #12Extra Fubar2018-05-17 08:29

    Hi Nige, Many thanks for your reply and time on this. I'll check for the QC origin this weekend (when I have access to the equipment). I actually would be surprised if it wasn't a CAT one because all the manuals I have (parts, operation, etc.) refer to it. I'll also get the bucket out this weekend to see how worn is the QC and post some more pics. Thanks,

  13. #13Nige2018-05-17 11:44

    Put it this way. When your particular machine left the production line it didn’t have a QC installed on it, not according to the factory build records anyway.

  14. #14Extra Fubar2018-05-22 21:40

    Hi Nige, Would you happen to know the new part number for 279-4300? Searching for this together with my serial number on parts.cat.com leads to no result (part not found). Thanks!

  15. #15Nige2018-05-23 04:33

    Looks like you will have to speak to Hewitt direct. 279-4300 shows as a good number with no updates.

  16. #16Extra Fubar2018-05-27 15:24

    Here are some pics of the coupler.

  17. #17Extra Fubar2018-05-27 15:25

    Pics of the pins with dimensions (about 12" for the bottom, and 15" for the top)

  18. #18Extra Fubar2018-05-28 22:39

    I'll order new pins tomorrow and new spacers for the thumb too. Depending on the loose, I'll also call in a welder. Looks like the quick coupler was already welded a bit in the past.

  19. #19Extra Fubar2018-06-02 12:13

    I got the pins yesterday, but it looks like the bucket was slightly modified because the pins are too short. I guess I'll mesure the diameter with a calliper and order custom length ones... oh well.

  20. #20Extra Fubar2018-06-03 20:25

    Unless someone has a better advice I think I'll go with pins like that: https://www.ebay.com/itm/Excavator-Bucket-Pin-40mm/153023245088

  21. #21Extra Fubar2018-06-06 19:16

    Good thing I measured it, its diameter is 45mm.