-
- About Us
- Cooperation
- News
- Offer
- E-shop
- Contact
- TRACK FINDER
- WYSZUKIWARKA SZYB
- Kategorie produktowe
-
ALL CATEGORIES
-
-
-
-
-
-
SLEW SYSTEM
-
-
-
-
-
AXLES
- TIE RODS
- KIT SPIDER FOR DRIVE SHAFTS
- DIFFERENTIAL
- MOUNT THE KNUCKLE
- KIT SPIDER FOR AXLE SHAFTS
- HUB / GEAR REDUCTION
- PROPSHAFTS
- SOLENOID VALVES / COILS
- FLANGES / COUPLING YOKES
- BEARINGS
- BUSHES / WASHERS MOUNT AXLE
- AXLE / DIFFERENTIAL HOUSING
- DRIVESHAFTS / CENTER JOINTS
- BOLTS / NUTS / STRAPS
- LOCK / CIRCLIP / CLIP
- CROWN WHEEL AND PINIONS
- SEALS
- OTHERS
-
-
-
-
-
-
-
-
ENGINE
-
-
-
-
-
COILS / SOLENOID VALVES
-
SWIVELS / TURNING JOINTS
-
PUMPS / STEERING VALVES / MOTORS
-
-
-
VALVES
-
HYDRAULIC HOSES / PIPES
-
RAMS
-
ACCUMULATORS
-
QUICKHITCHES
-
-
-
BOLTS / NUTS / WASHERS
-
PUMP DRIVESHAFTS
-
SEALS VALVES / PUMPS
-
OTHERS
-
-
-
-
-
-
-
TIMING
-
EQUIPMENT
-
-
LUBRICATION SYSTEM
-
-
INDUCTION / EXHAUST SYSTEM
-
SEALS / GASKET SETS
-
ENGINE MOUNTING
-
SERVICE TOOLS
-
-
-
-
-
-
STABILIZERS
-
-
-
-
-
-
FUSES / FUSE BOXES
-
RELAYS / FLASHERS
-
REVERSE ALARM
-
-
HEATERS / BLOWERS
-
BATTERY ISOLATER SWITCH
-
-
-
-
-
OILS
-
FLUIDS
-
-
-
PAINTS
-
-
-
-
-
-
-
GLASS / CAB GLAZING
-
-
-
RUBBER SEALS - GLASS
-
ASSEMBLY KITS / ADHESIVES
-
-
-
-
-
ADAPTERS
-
BOLTS / LOCKS
-
-
-
-
HYDRAULIC INSTALLATIONS
-
TOEPLATES
-
TOOTH RIPPER
-
-
-
HYDRAULIC HAMMERS / TOOLS
-
PLOWS
-
QUICKHITCHES
-
FORKS
-
-
-
EARTH DRILL / AUGER
-
SWEEPER / COMPONENTS
-
SWINGOTILT / PLATFORMS
-
-
-
-
-
ACCESSORIES
-
DECAL / STICKERS
-
-
-
GADGETS
-
CLOTHES
-
FAN ZONE
-
-
-
- SPARE PARTS SUITABLE FOR
- JCB
- CAT
- VOLVO
- KOMATSU
- CASE
- NEW HOLLAND
Excavator Swing Motor Failure: Symptoms and Diagnostics
Excavator Swing Motor Failure: Symptoms and Diagnostics
When the Machine Loses Its Precision
Is your excavator struggling to swing, jerking, or unable to hold the boom in position on a slope? A swing problem is one of the most frustrating failures, making precise and safe work nearly impossible. Although we commonly refer to it as the "swing motor," it is actually an integrated drive assembly, and the symptoms can point to a fault in one of several key components. This guide will help you preliminarily diagnose where the problem lies.
Anatomy of the Swing Drive Assembly
The entire mechanism that rotates the excavator's upper structure consists of three main parts, combined into one unit:
- Hydraulic Motor: The top part of the assembly. It is typically a piston motor that receives pressurized oil from the control valve and converts it into high-speed rotation.
- Planetary Gearbox (Swing Reduction Gear): The middle, largest part. Its job is to reduce the high speed from the hydraulic motor and multiply its torque.
- Pinion Shaft: The output shaft from the gearbox, ending in a small gear (the pinion) that engages with the large, stationary slew ring attached to the undercarriage.
Failure Symptoms: Motor, Gearbox, or Slew Ring?
The key to diagnosis is distinguishing between hydraulic and mechanical symptoms.
It's a HYDRAULIC MOTOR problem if:
- There is a lack of swing power: The machine struggles to swing the boom uphill or with a full bucket. This is a typical symptom of internal leakage in the motor and loss of pressure.
- The upper structure "drifts": After stopping the swing, the superstructure continues to slowly rotate on its own, especially on a slope. This indicates a problem with the motor's internal brake or cross-port relief valves.
- There are hydraulic oil leaks from the top part of the drive assembly.
It's a GEARBOX problem if:
- You hear loud, metallic knocking or grinding: The sound comes directly from the gearbox and intensifies under load. This is the sound of damaged bearings or broken planetary gear teeth.
- You find metal shavings in the oil: When changing the swing gearbox oil, a large amount of metal particles is a sure sign that the gearbox is destroying itself.
- The swing suddenly locks up: A fragment of a damaged bearing or gear can jam the entire mechanism.
It's a SLEW RING problem if:
- A "clunk" or "jump" occurs at the same specific point of rotation: This is a classic symptom of a broken tooth on the slew ring.
- There is a consistent, loud rumbling or "crunching" sound throughout the entire rotation: This indicates worn or damaged ball bearings inside the slew ring.
- The superstructure "rocks" on the undercarriage: Excessive play between the upper and lower frames is a sign of extreme wear in the slew bearing.
How to Care for the Swing System?
Cleanliness is Key
Contaminated hydraulic oil is the number one killer of a precision swing motor. Regular replacement of hydraulic oil and filters, such as those from the REDX brand, is the easiest way to prevent failure.
- Regularly change the oil in the swing gearbox according to the machine's manual.
- Regularly grease the slew ring bearing through its designated grease fittings.
- Operate smoothly. Avoid sudden, jerky starts and stops of the swing function, especially with a heavy load.
Problems with the swing on your Komatsu, Case, or Hitachi excavator? A precise diagnosis is essential.
Contact us. We will help you identify the source of the problem. Our offer includes complete new and remanufactured swing drives, as well as parts for their repair. Remember that a failure in the hydraulic system can lead to cylinder damage – check our offer for VICORTEX seal kits to comprehensively care for the entire system.
Related posts
WE OFFER PRODUCTS OF THE BEST BRANDS


















ul. Podkarpacka 57A, 35-082 Rzeszów
NIP: 813-352-97-49 REGON: 180286726
Opening hours
Telephone support - Monday - Friday (8:00 AM – 5:00 PM)
Order pick-up - Monday - Friday (8:00 AM – 4:30 PM)
[email protected]
[email protected]
Gadu-Gadu communicator
GG: 4185846 - Daniel
+48 17 864 31 00
+48 17 864 00 24
+48 17 864 25 96
Mobile phone
+48 607-700-547
+48 695-944-818
+48 691-330-531
+48 690-906-751
Fax
+48 17 864 31 20
