I did a float move for a farmer the other day and I noticed most of the bearing were shot on the bottom rollers, then I seen this!
Judging by the wear on the side of the segments I'd say something is out of alignment. I had a roller on a D7 do that, I think they get run so long that sooner or later the whole darn thing goes to pieces.
There is something crazy about that whole thing. The rail is shinny on the inside of the far side also so its rubbing the sprocket or something on the other side also. Is the rail correct for the machine? Maybe all components should be checked for compatibility to insure it is not a mix and match. The sprockets are well worn and getting long in the valleys but that should not give it side wobble.
Excavators now days will generally run through two sets of track rails and sprockets per each set of rollers. The chains and teeth might have 3,000 hours on them while the rollers could have 6,000 to 8,000 hours. I see things like that on logging machines quite a bit.
I think it's all original from the factory. Machine is a 20 ton new holland. Think is the same as kobelco? Has around 7000hrs.
If you look closely at the chains you will see that the links have so much wear in the pins and bushes that the bushes are starting to appear between the links. This would allow so much side movement on the chain when turning it will break the side off every roller and ruin the track guides in no time. Sorry to say it but new chains, sprockets and a few rollers will have to go on the shopping list.
our 336e has a roller like that...right near the sprocket. it was broken when we got it. it appears to have cracked do to an impact as theres not much wear on it.
And there you have it. All the U/C is absolutely shot, it's easy to see that from the one pin directly under the damaged roller that the joint is totally destroyed. Unless the OP is extremely lucky there will be more joints like that one. It'll probably need new tracks, track rollers, sprocket segments, idlers, & carrier rollers by the looks of it. Consider anything less than that list as a bonus.