If your excavator is tracking to one side there are a few things to look for. We recommend using a qualified and experienced hydraulic technician, who should check that the final drives are receiving the correct pressure from the hydraulic pump. If the correct pressure and flow is not being delivered to the final drives, this will affect their performance. The hydraulic lines should also be checked for blockages, and the condition of the tracks should be taken into consideration.
A good hydraulic technician will proceed with troubleshooting the issue, checking for issues thoroughly, giving due attention to the troubleshooting process.
All external factors should be considered before you decide to replace the final drives, to exclude other causes for the problem. If the reason for your machine tracking to one side is not due to the final drives themselves, you run the risk of damaging (or destroying) new final drive/s because the original cause of the problem remains.