Views: 0 Author: Site Editor Publish Time: 2026-10-01 Origin: Site
Ordering the wrong final drive is expensive — return shipping, lost weeks, and a machine that stays down. The fix is simple: measure your existing unit before ordering. This guide shows exactly what to measure on an excavator final drive to identify the correct replacement part.
Count the bolt holes on the sprocket (drive hub) where the track sprocket bolts on. Common counts include 18, 26, 30, and 36. The sprocket hole count is the first filter used to match a final drive.
Count the bolt holes on the frame (mounting) side of the final drive where it bolts to the track frame. This must match the machine's mounting pattern exactly.
Measure the diameter of the circle passing through the center of the bolt holes on both the sprocket and frame sides. Two units with the same hole count can still differ in BCD.
Measure the motor shaft diameter, spline teeth count, and shaft length where the travel motor connects. For complete assemblies, confirm the motor housing bolt pattern and pilot diameter.
Record the overall length and the reduction ratio if stamped on the housing. The ratio affects travel speed and torque output — a wrong ratio makes the machine travel too fast or too slow.
Clean the unit so bolt holes and stamped numbers are visible
Take photos of both mounting faces, the sprocket side, and any stamped part numbers
Write down: sprocket hole count, frame hole count, BCD (if measurable), and the OEM part number
Note the machine brand, model, generation, and serial number
Send these details to a supplier — accurate measurements let them match your unit against their catalog database in minutes.
Counting only visible holes without rotating the unit — verify the full circle
Measuring BCD across bolt holes instead of through the center
Ignoring generation differences (e.g., PC200-7 vs PC200-8 bolt patterns)
Ordering from the model name alone without checking hole counts
BN Gears' sales team matches final drives from measurements, photos, and OEM part numbers — with 12,000+ parts covering 600+ models in the database. Send your measurements and get a confirmed match before you order.
