When to Replace Final Drive Motors or Swing Motors: Signs, Causes and Solutions
Final drive motors and swing motors are critical hydraulic components in excavators and tracked construction equipment. They power the machine’s ability to move and rotate, and when they begin to fail, they directly affect performance, safety, and jobsite productivity.
This guide explains how to identify the signs of failure, understand the causes, and decide when replacement is the right move. It is also useful for buyers of second-hand machines and those sourcing aftermarket parts.
What Are Final Drive and Swing Motors?
Final drive motors are responsible for propelling the tracks or wheels of an excavator. They convert hydraulic pressure into mechanical force, enabling travel on the jobsite.
Swing motors power the rotational movement of the excavator’s upper body. This rotation is essential for operations like trenching, loading, and positioning.
These motors are highly precise and durable, but due to the nature of construction work, they are exposed to heavy loads, hydraulic pressure, and environmental wear.
Common Signs of Failure
Weak or Sluggish Movement
Machine travel is slower than normal, and swing function becomes less responsive. This is often caused by internal wear or hydraulic leakage.
Unusual Noises
Grinding, rattling, or whining during operation often indicates bearing failure or gear damage inside the motor.
Oil Leaks
Hydraulic fluid leaks from the motor housing can indicate damaged seals or cracks in the casing.
Excessive Heat
The motor heats up quickly during use. Overheating suggests friction or internal fluid contamination.
Jerky or Irregular Movement
Tracks or swing function move in an unsteady or uneven manner, usually caused by gear alignment problems or internal imbalance.
What Causes Motor Failure?
- Inadequate maintenance (neglecting oil/filter changes)
- Contaminated hydraulic fluid (with metal or dust particles)
- Overloading beyond design specs
- Age-related wear (often after 4,000 to 8,000 operating hours)
- Damaged seals leading to moisture or debris entry
When to Repair vs. Replace
Repair May Be Enough If:
- The issue is limited to external seals, hoses, or fittings
- The motor housing and gears are in good condition
- You are not under urgent time pressure
Consider Replacement If:
- Gears, rotors, or internal components are heavily worn
- There is major internal contamination
- You need fast turnaround with warranty support
- You plan to resell or export the machine
Recommended Lifespan by Machine Type
| Equipment Type |
Final Drive Motor |
Swing Motor |
| Mini Excavator (1–6 ton) |
4,000–6,000 hours |
4,000–5,000 hours |
| Medium Excavator (6–20 ton) |
6,000–8,000 hours |
5,000–7,000 hours |
| Large Excavator (20+ ton) |
8,000–10,000 hours |
7,000–9,000 hours |
To avoid compatibility errors, always provide your supplier with:
- Brand and model of your equipment
- Serial number of the original motor (if available)
- Clear photos of the current motor (including the nameplate)
- Description of the problem
Where to Buy Quality Replacement Motors
China is one of the largest global suppliers of replacement parts for prominent brands such as Caterpillar, Komatsu, Hitachi, Sany, Doosan, Hyundai, and Volvo. Many motors are in stock for immediate shipment.
Our Offer
Frequently Asked Questions (FAQ)
Can I use a rebuilt motor instead of a new one?
Yes. Rebuilt motors are more cost-effective and often come with a short-term warranty. They are a practical choice if sourced from a reputable supplier.
How long does shipping take from China?
Air shipping typically takes 5–10 days. Sea shipping can take 3–6 weeks, depending on the destination.
How can I confirm compatibility?
You’ll need to match part numbers or confirm fitment with your supplier using the machine model, serial number, and photos.
Get a Fast Quote Today
If your machine is showing signs of travel or swing issues, don’t wait until a complete breakdown stops your work. Contact our team today for fast support and parts sourcing.
Email: tommy_jun@zekungroup.com
WhatsApp: +86-193-5217-0743
Website: www.zekunmachinery.com
Your message must be between 20-3,000 characters!
