Morning I don't know a lot about excavators but looking for one for farm use. Anything you can tell me would be helpful. When they tell you the percent of undercarriage how is that measured? And at what percent should it be replaced before you start having trouble? Just for a 100 hours a year how poor of undercarriage can you get away with? Without having trouble.:Banghead TIA farmlion
Ok. I found some info on youtube. But they never mentioned wear in pins and bushings on rails. And that's what i was kinda most concerned about. So basically if they all seem tight and there's still some tightener left its all good??
If you are only running 100hrs a year, if you can keep the uc tight. Run it till it breaks. You can also take a link out of the chain to get them to tighten again. I ran one till the bushings wore through. than it started to climb. As long as you can keep them with proper tension they will not normally derail. will last a long time.
Excavator undercarriage is kind of the dinosaur version of what is installed on crawler tractors now days. Basically the chains are nearly the same as what was installed on crawlers built in the nineteen sixties. The pins and bushings are sealed between the joints usually with some type of fiber seal now days. They used to have a belleville washer. Sealed and lubricated links are not used on excavators so most coat the outside of the pin and inside of the bushings with a grease when they are assembled new. The grease doesn't last long and can cause a problem called bridging where the links seize in the curved position. Once the links have seized they as a rule don't straighten out again. Since most excavators don't walk the distances that crawlers do, the undercarriages as a whole are smaller in comparison to the weight of the machine. The chain links themselves usually don't wear off much but the strain on the links is greater because the excavators will be nearly twice the weight. Internal wear between the pins and bushings shows up in how far forward on track frame the front idlers are adjusted out. The idlers have a block on each side that fits into the track frame. When the front of those blocks are even with the front of the track frames for most machines the internal wear on the tracks is about 100%. The second clue to the wear in the chains is seen by looking straight down on the link junction as the tracks go over the curve of the idler or sprocket. On new tracks there will be no space between the big end of one link and the small end on the other. On worn out tracks there will be space between the links in that joint. On really worn tracks you might be able to almost put your finger in that space and touch the bushing protruding through the small end of the link. To summarize this, when the front idler blocks are at the ends of the track frames and there is a lot of space between the link joints, the chains are for the most part 100% worn. If the idler blocks are way back in the track frames but there is a lot of space between the link ends you will need to count the number of pads on the chains and find out how many are supposed to be there. It is common to take out a link when the chains have stretched out.
You guys pretty much nailed it but I like more opinions when looking for advice so I'll agree and add a little more. As was said count the links. If they are original, you can take out one for a farm machine. Excavators generally only carry their weight and don't pull so there is a lot of forgiveness there. If you work on slopes, you can toss this all out the window. I bought an old Case hoe many years ago with wore out tracks. I didn't really know the difference back then and the price was right. The tensioner was at the end of it's stroke and I put another 1200ish hours on it before I pulled out a link. I have another 1500+ hours on it after that and it's still going strong. I try to haul it when possible and it's only my back-up machine. I have not put one single part in that UC. I have a newer excavator and dozer which both have good to great UC's but I have to keep used rollers and idlers on hand for them. Long story short, as long as you aren't working steep slopes and are aware of what's going on under you, you'll be fine with a weak UC on an excavator. Good luck
Thanks guys. Almost sounds like Ive maybe been worrying to much about the undercarriage for small hours a year. Is there somewhere online where i can find the amount of links its supposed to have or will have to talk to a dealer?
Twisted mentioned it at least twice, and it is definitely something to keep in mind if running slopped out rails. They do not like slopes or uneven ground at all. What happens is the tracks get out from underneath the bottom rollers. On older machines, what happens next is you start turning that direction, or just flat out stop. Then you have to lift that side up off the ground to let the track get back into place. Not trying to scare you, if you're just going to be tracking around in the field pulling rocks/burying junk or random stuff around the yard, you'll probably be just fine. Start crawling around on top of a road trying to do culverts or clean ditches, and it'll be another story. As the others have mentioned, count the links and see where the idlers are at. If you have the correct number of links, and the idlers are inside the frame at all, you'll be fine for a long time.
Good day familon I suggest you treat wear percentage with a degree of caution in our experience an undercarriage with 50% remaining will wear much quicker than the original wear pattern, this may be due to the hardening of components decrease with wear depth. Visit excatech.org for more information. Kind regards Uffex
My opinion is that as long as the tracks are not falling off too often, and they will stay on in order to load it on a trailer, if you need to move it, then they will work, and especially for the limited 100 hrs per year you are talking about. I have machines in my yard that are low use that have the bushings worn through, pins wore to 1/4 their original size, and sprockets that you can hardly tell had teeth. Replacement is expensive, and on many older machines, more than the machine is worth, so just keep them working until no longer feasible. Just remember, if your work involves working on steep ground, you will need to do it different.