Tracks not flexing as they should due to pins/bushings sticking. This is basically a farm machine that sits more than it is used. The pins and bushings are seizing up leading to the tracks not flattening out as they come over the idler or sprocket. Clunks along when moving due to those chain joints that do not release when tracking. Seems back when I first was on this site for guidance with rebuilding the finals -I had read about using diesel fuel and squirting it each effected link and work the tracks forward and backwards. I also think in noted putting a little more track tension. I have been trying those tips and not getting too far yet. I have seen a little improvement and have spent a couple hours on it - here and there with the fuel oil tip and just a little more tension on the tracks. Any other advice? Some heat perhaps? or would that be a problem with the seals? The chains, sprockets, idlers were all new just prior to me acquiring the excavator +/- 6 years ago. The machine has not been used for more than 200+/- hours since, and assume that is why it is happening. Thank You..
Best thing for stuck track pins is water. If you can find a puddle and sit the machine in it for a few hours to soak, even better. Then track back and forth, rinse, and repeat.
Good day r74 Having been involved with this issue on a few occasions I have attached a couple of documnents that may be of interest. Kind regards Uffex
Thank You for the replies, and attachments on the subject. The attachments were good to read through. In my lack of experience with this type issue, I had thought it was water that had seeped in and caused the issue in the first place. Thank You for that tip. I do have the ability to get them in water and will try that for sure. Hope you both are healthy and well in light of all that is going on in the world today. Nick
It most probably was. If you can get something into the pin/bush area of the tracks then after a sufficient soaking and exercise they ought to free up. However it must be pointed out that if water was the cause of them seizing in the first place then they are likely to seize up again unless they are exercised (relatively) frequently.
It used to be that I only saw the issue in tracks that had been working in salt water. The issue is called bridging and started happening more and more when manufacturers started using some kind of grease in the build of the track chains and then started calling them sealed and lubed. The type of track chains used on excavators were called sealed for years and were used on all crawler mounted machines. The advent of SALT tracks meant that sealed tracks were only used on excavators. The marketing people wanted customers to think they were getting something better than the standard type of tracks invented in the 1930s and 1940s so they put the grease in the bushings, pushed the tracks together and called them sealed and lubed. The grease really has little if any bearing on the life of the track chains. It's all marketing. As Mr Uffex's excellent pages state, there is nothing you can do about it other than paying to have the chains pressed apart, cleaned and reassembled. The issue is a bother to many operators but is not really much of a problem unless so many links are bridged that the front idlers are pulled back so hard they are compressing the recoil springs.
Good day folks A contact has given some information that may help. Kind regards Uffex
I was looking at my tracks today and thinking of a long shot method to add lube to the affected link. Can you drill and tap to add a zerk fitting in from the top or bottom in order to inject penetrating fluid directly into the bushing/pin? Not sure how hard the link is but I bet you can drill and tap it. The drill will bottom out on the bushing and you'll probably have to use a die grinder with a long burr to pierce the bushing to get to the pin. If you can get to the pin, replace the first inch of grease in the connector hose with your favorite penetrating fluid and see if you get some to flow through into the pin/bushing. Might have to do small pumps over a period of a day. Once done, remove the zerk and plug up the hole. No idea on how hard or thick the the bushing is but since the link is shot, this might be worth while. Any one know the usual hardness and thickness of the link and bushing for this size machine?
F'kin hard. In fact even harder than that. Carbide might touch it but I wouldn't even guarantee that, anything else would have no chance. I've never head of that being done.
Good day Normally those parts are of borran alloy very hard tapping a thread in that material would be impossible, suggest you push the pin out clean - lubricate and reinstall the pin. Sorry if I appear negative to your suggestion. Kind regards Uffex
No negativity perceived when just saying the facts. Unfortunately I thought that was the case, otherwise this trick would probably have been done multiple times over. I figured there is enough wear in the pin/bushing (at least 5-10 thousandths) so you can get some lube to flow around the wear surfaces and break up the gunk...if you could get to the wear surfaces. I grew up in machine shop as my dad was a tool and die maker for the government. Injecting oil into frozen shafts/bearings or using grease gun pressure to pop out blind pins, split matings, etc. were just a few of the many, many tricks I learned. It was amazing the range of tools and knowledge I had access to in my dad's shop. Back to common sense: My guess is pushing out and replacing pins in the field is a common practice and there is bound to be a service truck with the portable hydraulics at every dealership (regardless of brand), right? It's just a matter deciding if fixing the track is worth the service $$.
Good day LCA I must admit the first time this landed on my table I found it strange that track's which made 1000hrs + would get tighter - normally the wear is the normal complaint. Many hours spent on different machines with the same illness did not find a cure other than pushing out the pin suffecient to clean and lube, I guess you must calculate the cost of replacement against repair. Kind regards Uffex
Keep in mind that a standard pin will take a whole lot more press to push out of both fitted sides of the track rails. When pressed in a shop only one side is pressed at a time. The rail is pushed onto the pin. As I recall that is usually around 30 tons for your size of machine. In the field you will have to push the pin all the way through the chain which more than doubles how hard the press has to push. Add to that the lube that has turned into cold weld and the 100 ton track press may or may not be able to push the pin without breaking something.