Ordering the correct final drive is crucial for the proper functioning of heavy equipment such as excavators, bulldozers, and other construction machinery. A final drive is a critical component that transmits hydraulic power from the pump to the wheels or tracks. If the travel motor is not measured correctly, it may not fit properly with the rest of your undercarriage components, leading to alignment errors, safety concerns, and costly downtime.

To avoid fitment issues, you should always measure the physical dimensions of your old travel motor before ordering. In this guide, we walk you through the five key measurements (A, B, C, D, E) that ensure a 100% correct match.

The 5 key dimensions to measure (A/B/C/D/E)

When requesting a quote or verifying compatibility, you will need to measure the following dimensions in millimeters:

• A: Sprocket Hub Pilot Diameter: The outer diameter of the circular hub where the sprocket sits, or the inner center-hole diameter of the sprocket itself.
• B: Frame Pilot Diameter: The outer diameter of the circular flange section of the travel motor that inserts into the main frame of the excavator.
• C: Sprocket Bolt Circle Diameter (PCD) & Hole Count: The distance between two opposite bolt holes on the sprocket flange, along with the total number of bolt holes (e.g. 9, 12, or 18 holes).
• D: Frame Bolt Circle Diameter (PCD) & Hole Count: The distance between two opposite bolt holes on the frame side, along with the count of threaded holes used to secure the drive to the undercarriage.
• E: Sprocket Width or Depth: The depth or height profile of the sprocket mounting surface relative to the frame flange.

Final drive measurement diagram

Use the diagram below as a visual reference when taking measurements on your travel motor:

Related technical guides and link building

If you are experiencing drive issues, you can refer to our final drive troubleshooting guide to find the root cause. If your machine is tracking unevenly, read about final drive speed difference issues. You should also check our articles on signs your final drive is in bad condition and learn how to maintain a final drive to prevent early failures.

If you already have your measurements and are ready to install, read our step-by-step guide on how to replace a final drive. For information on other excavator components, explore our overviews of what is a final drive, hydraulic main pumps for excavators, and swing devices for excavators.

For more guides, please visit our Mecatra blog overview. If you have your dimensions ready, fill out the form below or email us at info@mecatra.com to receive a quote within 1-3 business hours.