I have a couple of 953's that are to the point they want to walk off the tracks while turning. The under carriages are about worn out. Pins have been turned. The idler and rollers still turn and look to have a little life left in them. I have replaced the sprockets segments and it looks like I still need to do some work. The rails that are currently on the machine are CAT rails. Question 1. Do you get more value by just replacing a few parts at a time. Another words, Run it till it is completely worn out... I am considering just putting rails on to start with. Question 2. I ran into another 953 owner and he stated that he bought a complete aftermarket under carriage and that he could not keep the tracks on the machine. He ended up taking it off selling it for a loss and purchasing a new CAT under carriage. Have any of you experienced this? Question 3. How far can you push it till it is not worth the problems... When must you replace the bottom rollers and idler assemblies? Thanks
Replace everything...the wear on parts will big worse....front idler...segements and chains (rails)
Cheap aftermarket bad....but had very good luck with quality jobber stuff
Unfortunately the old parts will wear anything you put on new much, very much faster. Best is to replace everything at once.
Get someone out to measure all the components and give you a report. Cat dealers have people who will do that for free on the chance that they can sell you new components. Once you know where you are at, then you can make informed decisions. In theory all the components should wear out at the same time. In actuality that never happens. You will always throw something away that has some life left in it. Knowing that will allow you to replace components to maximize the return on investment for the whole machine. As far as your tracks coming off the frames, there are plenty of reasons that can happen. Track frames bent or loose and tracks out of alignment with the sprocket. Loose front idlers, broken bottom rollers, front idlers at the end of their adjustment, track adjuster cylinders leaking and I'm sure someone will bring up something I've forgotten. If you do replace everything remember that all these items still apply and will need to be checked when you put the machine back together.
^^^^^^^^ What he said ^^^^^^^^ I suggest to call your local Cat dealer and ask for a PSSR (Parts & Service Sales Rep) to come to your machines. This is a free service, and they will start salivating when you tell them that you're potentially in the market for undercarriage for 2 machines. The PSSR will be trained to measure undercarriage wear, present you with a report showing the current condition right down to every individual roller, and suggest possible repair options. He will also comment on the condition of all the items mentioned by John above that affect the life of the replaceable undercarriage components such as rollers, idlers, & rails. I'm not sure about the 953 but for many models there are "full fat" and "budget" options for undercarriage. Make sure you ask about that possibility.
Agree totally with John C and Nige, cannot go wrong having those in the know inspect and checking with CAT on budget options. Personally the Chinese knockoff UC is pretty worthless unless use on a farm limited hours a year.
Paraphrasing your thread title - "Undercarriage rebuild questions. Longevity vs Operating Costs." Put simply, when it comes to undercarriage in general terms you get what you pay for ........ higher price = longer life. The only caveat apart from that is the realization that undercarriage works as a SYSTEM, not a load of unconnected parts. Changes to one part of the system can affect the way other parts of the system behave.