I'm looking at a KX121-3 with just under 2900 hours on it. It has its original steel tracks and they seem to have a lot of play in them. I have been looking for some kind of specification for an allowable amount of wear that could be measured on the machine(i.e. a certain amount of pins = X inches + a certain max amount for wear), but haven't had any luck. The sprockets are smoked on the machine and it is being sold as is. I just don't want to get into a situation where after new sprockets are installed and the rest of the UC is inspected/repaired as needed, there is a problem with the track being too worn out and coming off the machine, or wearing out sprockets too fast. I didn't ask the dealer because I have a feeling they will not give me the info I really want. I would rather show up to inspect the ex thoroughly with all my own info. Thanks in advance for any info or advice you guys might have for me. I've been lurking on here for a while and really appreciate the help some of you are able to provide for newbies like me. Matt.
My KX91-3 has steel tracks and just over 1000 hours and is starting to show some wear. I would expect by the time it hit 2900 hours they would be near replacement time. I don't know the spec's but bet it would not fix the problem with new sprockets and might be a waste of money. In Canada it would probably cost about $5000.00 to replace the tracks and sprockets. If the 121 is like the 91 you could put rubber tracks on and only have to remove a couple of guides and change the spring pressure to accommodate them. So if rubber would work it would only cost less than $2000.00 including sprockets, which are the same for steel or rubber.
To check your track wear you should be able to find out what pitch the original track is. Pitch is links per inch, or maybe feet in this case. Then measure your track and see what you get. It may help to measure a longer distance to get a feel for the wear. Also I believe caterpillar dealers have undercarriage specialists that can measure wear. Machine doesn't have to be cat, cat just wants to sell you the new steel. Hope that helped.
Thanks. Machine was sold by the time I got back to look at it.