We are having problems with our ZX35u Hitachi. The track has started falling off, three times in the past two weeks, the adjuster and rollers seem to be fine, the track looks like it is bent. I installed these last year, not sure how many hours on them. Is this a common problem? I checked our other Hitachi and it looks like it is bent too. Our Cat and JD have the factory tracks and look fine. Our machines work primarily in the street, I wonder if twisting and turning on asphalt would cause this? If you lift the track off the ground and slowly rotate the track, you can see where the track is bent? Any comments or suggestions?
Have both hitachi's been on the same site recently or driven by the same operator?? - may help you narrow down the possible cause. I have never heard of this before but I am pretty new to this game!!!! Please keep us posted on any findings.
They were not on the same job, but both work under the same conditions. Different operators. I called the dealer today and the service manager said he would like to see the machine. I explained to him that I removed the idler thinking it was a bad bearing, but it is fine, when you roll the track the idler wants to walk back and forth where the track is bent. He said they can wear in this area and welding a few beads would tighten that up, but no explanantion for the bent track. I am probably going to buy new tracks, but since one side seems worse than other he suggested swapping sides and see what happens.:beatsme
Hi red bank If you've already checked the idler bearing, I would make sure the idler guides are good. It's fairly common on a lot of excavators for the fork end of the track frame to open up and let the idler move from side to side. If your machine has carrier rollers, check these for alignment. Bent shafts or mounts aren't uncommon. Also check the recoil spring isn't broken.
It sounds to me like you have a track that has steel links inside the rubber. In the early days of rubber tracks on excavators I used to see the steel links come apart and the only thing that held the track from breaking was what was left of the other side of the link and the rubber itself. A couple of photos would go a long way in diagnosing the issue.
Has either of the drive motors been replaced lately? The manufacturer that makes that drive motor offers a 50mm or 70mm offset on the sprocket, that's enough to make it "bend" and jump the track. The incorrect sprocket or excessive wear would also do the trick. I agree with John C. photos would help and more history on the maintenence of the machine.
No final drives have been replaced, only maintenance done has been replacing the tracks, along with routine oil and filter changes. I will try to get some pictures.
Are they steel or rubber tracks ? If they are steel you could have twisted a chain link or two . Running a steel track machine in the middle of a single lane road is hard on them . The whole machine weight is suspended by the insides of the track plates , i always walk too one side of that sort of road . It keeps the track plates flat on the ground which stops the pins and bushes being stressed and also the rollers and sprockets .
Well we are one step closer to figuring out what the problem is, the track broke today, ordered two new ones, will be here Wednesday, I plan on putting them on the machine and checking over everything real close. Any ideas or suggestions?
I put the new tracks on today, the one thing I noticed is the tracks I had were too wide-I bought the new tracks at the Hitachi dealer, the ones that were bent came from a vendor. I noticed when I put the old ones on that they were wider, but I thought this could be a good thing. Now I think that was the problem with the tracks bending. I checked my records and I have 1200 hours on the old tracks. The original tracks lasted 1700 hours. I measured the frame at the idlers and both sides were the same, checked play at the idlers, both sides the same, everything looks to be the same for both sides. The new tracks worked great and ran straight. We will see how they do.
$$$$$$ will fix a problem almost every time...