Mini Excavator Final Drive Replacement Cost: Kubota, Bobcat, Cat, John Deere

When a mini excavator loses drive to one track, spins in circles, or will not pivot turn properly, the final drive is the first suspect. On mini excavators, the final drive is a hydraulic travel motor paired with a planetary reduction gearbox, one on each side. Replacing one is a $1,400 to $5,800 job per side depending on the machine, parts source, and whether the planetary needs attention at the same time. Here is what drives that range.

What the Final Drive Does on a Mini Excavator

Mini excavators use individual hydraulic travel motors to drive each track. The travel motor converts hydraulic flow from the main pump into rotational force, which is then multiplied through a planetary reduction gearbox inside the sprocket hub before it reaches the track chain. When the travel motor fails, the affected track loses power. When the planetary reduction fails, you get grinding noise, oil loss from the hub, or a track that turns intermittently under load.

These two components (the motor and the planetary) are often serviced together because they share a housing and replacing one while leaving the other on a high-hour machine is a common cause of a second repair bill inside a year.

Mini Excavator Final Drive Replacement Cost

A final drive replacement on a mini excavator runs $1,400 to $5,800 per side, parts and labor. Single-motor replacement on a smaller machine with good parts availability sits at the lower end. Full assemblies on larger minis (7-9 ton) or machines with contamination damage run higher.

Machine	Labor Hours	Parts Cost	Total Estimate
Kubota KX040-4 / KX057-4	3-6 hrs	$900-$2,200	$1,400-$3,900
Bobcat E35 / E50 / E55	3-6 hrs	$900-$2,200	$1,400-$3,900
John Deere 35G / 50G	3-6 hrs	$900-$2,200	$1,400-$3,900
Cat 305.5E2 / 306	3-6 hrs	$1,000-$2,400	$1,600-$4,200
Kubota KX080-4	5-8 hrs	$1,400-$3,200	$2,200-$5,200
Cat 308E2 / 308 CR	5-8 hrs	$1,400-$3,500	$2,200-$5,500
Bobcat E85 / E88	5-8 hrs	$1,500-$3,600	$2,300-$5,800

Ranges cover remanufactured travel motor assemblies through OEM new. Shop rates of $85-$135/hr assumed. Add $300-$800 if the planetary gearbox needs separate service. Two-side replacement roughly doubles parts cost with some labor savings from simultaneous access.

Travel Motor vs. Full Assembly: Which Do You Need?

On most mini excavators, you can buy either the travel motor alone or a complete final drive assembly that includes the motor and the planetary gearbox as a single unit.

A travel motor-only replacement makes sense when the motor tests bad (low or erratic pressure output, internal leakage) but the planetary still has clean oil, no metal in the gear cavity, and smooth gear engagement. Many shops verify planetary condition by opening the drain plug and inspecting the oil before deciding.

A complete final drive assembly replacement is the right call when the planetary shows milky or metallic oil, there is bearing noise in the gear housing independent of the motor, or the machine is high enough hours that doing two separate jobs makes less sense than replacing the whole assembly once. Full assemblies cost more upfront but reduce the risk of a second job on the same machine within the service life.

Signs Your Mini Excavator Final Drive Is Failing

• Machine pulls or walks to one side under power. If the machine tracks straight when coasting but curves to one side when you apply travel pedal, the travel motor on the lagging side is producing less torque than the other. This is the most common early symptom.
• Cannot pivot turn. A mini excavator should be able to spin in place with one track forward and one in reverse. If one side will not hold against the other, the motor on the weak side is suspect.
• Track slipping or freewheeling at low speed. The final drive holds the track position when you stop on a slope. If the machine creeps downhill when you release the pedals, the travel brake inside the motor is not holding. This is also a safety issue and should not be deferred.
• Oil on the outside of the final drive housing or under the sprocket. Final drive oil lives inside the planetary housing. Oil on the outside means the hub seal has failed. Running the planetary dry accelerates gear and bearing damage fast.
• Grinding or clunking from one track side. Planetary gear wear shows up as a metallic grind that changes with travel speed, not engine speed. A clunk when you apply travel pedal that was not there before points to worn sun gear splines or a damaged planet carrier.

OEM vs. Remanufactured Final Drive Assemblies

• OEM new assembly: Highest cost, correct specs from day one, full factory warranty. The right choice for low-hour machines or machines still inside an extended dealer warranty period. Kubota and Cat OEM travel motors carry the most reliable supply chain in the mini excavator segment.
• Remanufactured (reman) assembly: 30-50% below OEM. Rebuilt to original tolerances with new seals, bearings, and wear components. Most carry a 6-12 month warranty. The standard choice for out-of-warranty machines. Confirm the reman unit matches your pump serial number, not just the general model, because flow and pressure specs vary mid-model-year on several Kubota and Bobcat lines.
• Aftermarket travel motor: Budget option. Quality varies widely. Use a supplier that lists your specific OEM part number for cross-reference, not just operating weight or flow class. A motor with a close-but-wrong shaft spline, port orientation, or brake spring rate will cause problems from the first hour or fail gradually in a way that is hard to trace back to the part.

What to Check Before You Approve the Job

Two checks matter before you commit.

First, have the shop pull a hydraulic flow test on the travel circuit. Low pump output pressure at the travel motor is sometimes the real problem, not the motor itself. A motor that tests fine under load has a root cause upstream. Replacing the travel motor without checking pump pressure at the circuit is a setup for a second diagnostic job.

Second, know what the machine is worth. A $2,500 final drive replacement on a 2021 Kubota KX057 with 1,800 hours is less than 7% of the machine's market value. That math works. The same job on a 2010 KX057 at 9,000 hours with worn tracks and deferred service history requires a different conversation. EquipBook's free valuation tool gives you trade-in, private party, and dealer retail numbers in under 60 seconds so you can run that math before you authorize anything.

Get a Repair Cost Estimate for Your Machine

Final drive replacement costs vary by machine size, parts availability, and your shop's rate. For a range specific to your make, model, and the symptoms you are seeing, use EquipBook's free repair cost estimator. Describe what the machine is doing and get a number to compare against any shop quote before you hand over the keys.

See also: mini excavator hydraulic pump replacement cost, compact excavator final drive replacement cost, and excavator final drive replacement cost for final drive repairs across other excavator classes.