MrBill, No problem, glad to help if I can. I'm trying to learn about all this crawler stuff myself as well. The pins connect the chain links together. They also mesh with the sprocket and transmit the power to the track. The bushings are inside the pins and allow the links to freely pivot so the chain can flex around the sprocket and idlers. Once the pins and bushings are worn to the 25% wear limit (or 75% of their useful wear has been consumed), then they should either be replaced or "turned". The process of turning involves removing the tracks, and then all of the pins in each link on the track are pressed out using a powerful hydraulic ram fixture. Then they are rotated 180 deg and pressed back in. What this does is rotate the less worn side of the pins/bushing to the primary wear side...which will shorten your track and allow you to get more use out of your pins/bushings. From what I've heard though, turning pins and bushings isn't always such a hot idea, especially for small-midsize loaders. Something to the extent that you really don't get much additional wear out of the turned pins bushings. Or in other words the turned pins and bushings don't really buy you another 100% wear cycle. Usually it is advised to simply replace the pins and bushings altogether with new ones while you're paying for the pin press labor. However, on the big dozers, turning pins and bushes is definitely worth it. It can be expensive to have a dealer show up and remove your tracks (or tow away your whole machine), take your tracks to their shop, turn the pins/bushings, and then return and reinstall. It can easily go over $1000 for this procedure (from what I've heard anyway)...but some people remove and install their own tracks and know someone locally that has a pin press who might only charge them ~$500. I've never removed my tracks, but from what I understand it's something a shadetree mechanic can probably do. You need a 15lb sledgehammer, a drift, a VERY trusting friend, an oxy/acetylene torch with a rosebud tip, and a bucket of ice water (for when you reinstall). If you're mechanically inclined and have access to a machine shop, you might actually build your own pin press (like a guy I see on the RedPower forum). But this can be an extremely dangerous process for an amateur, it takes serious force to remove those pins, and if something snapped or went wrong, it WOULD be lethal. Another option is to simply replace your chains altogether. I've heard that a set of new chains for smaller crawlers can be had for ~$2000. This would give you brand new links, pins and bushings. So if your links are down quite a bit in addition to needing a pin/bush turn, this would be a good option. Of course finding a nice used set of tracks with lots of wear left (at a good price) would be even better. Lastly, if you do go with new pins, be aware that if your sprockets are severely worn, this will cause accelerated wear on the pins and sprockets. So, replacing your sprockets is also advisable under these circumstances. (I know...$$$$!!!!) Good luck...
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