Yanmar. One track went into neutral. Are there solenoids or is it a hydraulic issue? I checked the final drive and there didn't appear to have any metal in it.
Your post is a little vague. Do you mean that the track freewheels? Or it won't move at at all? Both have entirely different repairs.
The track freewheels.
That tells me the spline on the sungear shaft is kaput. Depending on the series it may have a coupler which connects to the out put shaft on the motor or it'll connect to the rotating group in the hydraulic motor.
Thank you very much. I appreciate the help. We're working on it. (It's a Yanmar V10 35, if I need ask anything more.)
If you can post a photo of the hub from the outside and of the motor, it'll help identify it.